X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fwrite.c;h=2effd7dbd8fbf8fcca7224213695023fc45d148b;hp=497158999c807fb0ba6c0d0a8831a70f22f5b082;hb=30cfd915ede8a2b24b693525ff835b2f03220cc9;hpb=35dd893208119869db6a90b1d1663f9aea88a3f7 diff --git a/src/write.c b/src/write.c index 49715899..2effd7db 100644 --- a/src/write.c +++ b/src/write.c @@ -6,8 +6,7 @@ */ /* - * Copyright (C) 2010 Carl Thijssen - * Copyright (C) 2012 Eric Biggers + * Copyright (C) 2012, 2013 Eric Biggers * * This file is part of wimlib, a library for working with WIM files. * @@ -25,434 +24,2216 @@ * along with wimlib; if not, see http://www.gnu.org/licenses/. */ -#include "wimlib_internal.h" -#include "io.h" -#include "dentry.h" -#include "lookup_table.h" -#include "xml.h" +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#if defined(HAVE_SYS_FILE_H) && defined(HAVE_FLOCK) +/* On BSD, this should be included before "wimlib/list.h" so that "wimlib/list.h" can + * overwrite the LIST_HEAD macro. */ +# include +#endif + +#include "wimlib/endianness.h" +#include "wimlib/error.h" +#include "wimlib/file_io.h" +#include "wimlib/header.h" +#include "wimlib/integrity.h" +#include "wimlib/lookup_table.h" +#include "wimlib/metadata.h" +#include "wimlib/resource.h" +#include "wimlib/write.h" +#include "wimlib/xml.h" + +#ifdef __WIN32__ +# include "wimlib/win32.h" /* win32_get_number_of_processors() */ +#endif + +#ifdef ENABLE_MULTITHREADED_COMPRESSION +# include +#endif + #include +#include +#include + +#ifdef WITH_NTFS_3G +# include +# include +# include +# include +#endif + +#ifdef HAVE_ALLOCA_H +# include +#else +# include +#endif + +#include + +#ifndef __WIN32__ +# include /* for `struct iovec' */ +#endif + +/* Chunk table that's located at the beginning of each compressed resource in + * the WIM. (This is not the on-disk format; the on-disk format just has an + * array of offsets.) */ +struct chunk_table { + off_t file_offset; + u64 original_resource_size; + u64 num_chunks; + u64 table_disk_size; + unsigned bytes_per_chunk_entry; + void *cur_offset_p; + union { + u32 cur_offset_u32; + u64 cur_offset_u64; + }; + /* Beginning of chunk offsets, in either 32-bit or 64-bit little endian + * integers, including the first offset of 0, which will not be written. + * */ + u8 offsets[] _aligned_attribute(8); +}; -/* Reopens the FILE* for a WIM read-write. */ -static int reopen_rw(WIMStruct *w) +/* + * Allocates and initializes a chunk table, and reserves space for it in the + * output file. + */ +static int +begin_wim_resource_chunk_tab(const struct wim_lookup_table_entry *lte, + int out_fd, + off_t file_offset, + struct chunk_table **chunk_tab_ret) { - FILE *fp; + u64 size = wim_resource_size(lte); + u64 num_chunks = wim_resource_chunks(lte); + unsigned bytes_per_chunk_entry = (size > (1ULL << 32)) ? 8 : 4; + size_t alloc_size = sizeof(struct chunk_table) + num_chunks * sizeof(u64); + struct chunk_table *chunk_tab = CALLOC(1, alloc_size); + + DEBUG("Beginning chunk table for stream with size %"PRIu64, size); + + if (!chunk_tab) { + ERROR("Failed to allocate chunk table for %"PRIu64" byte " + "resource", size); + return WIMLIB_ERR_NOMEM; + } + chunk_tab->file_offset = file_offset; + chunk_tab->num_chunks = num_chunks; + chunk_tab->original_resource_size = size; + chunk_tab->bytes_per_chunk_entry = bytes_per_chunk_entry; + chunk_tab->table_disk_size = chunk_tab->bytes_per_chunk_entry * + (num_chunks - 1); + chunk_tab->cur_offset_p = chunk_tab->offsets; + + /* We don't know the correct offsets yet; this just writes zeroes to + * reserve space for the table, so we can go back to it later after + * we've written the compressed chunks following it. */ + if (full_write(out_fd, chunk_tab->offsets, + chunk_tab->table_disk_size) != chunk_tab->table_disk_size) + { + ERROR_WITH_ERRNO("Failed to write chunk table in compressed " + "file resource"); + FREE(chunk_tab); + return WIMLIB_ERR_WRITE; + } + *chunk_tab_ret = chunk_tab; + return 0; +} - if (fclose(w->fp) != 0) - ERROR_WITH_ERRNO("Failed to close the file `%s'", w->filename); - fp = fopen(w->filename, "r+b"); - if (!fp) { - ERROR_WITH_ERRNO("Failed to open `%s' for reading and writing", - w->filename); - return WIMLIB_ERR_OPEN; +/* Add the offset for the next chunk to the chunk table being constructed for a + * compressed stream. */ +static void +chunk_tab_record_chunk(struct chunk_table *chunk_tab, unsigned out_chunk_size) +{ + if (chunk_tab->bytes_per_chunk_entry == 4) { + *(le32*)chunk_tab->cur_offset_p = cpu_to_le32(chunk_tab->cur_offset_u32); + chunk_tab->cur_offset_p = (le32*)chunk_tab->cur_offset_p + 1; + chunk_tab->cur_offset_u32 += out_chunk_size; + } else { + *(le64*)chunk_tab->cur_offset_p = cpu_to_le64(chunk_tab->cur_offset_u64); + chunk_tab->cur_offset_p = (le64*)chunk_tab->cur_offset_p + 1; + chunk_tab->cur_offset_u64 += out_chunk_size; + } +} + +/* + * compress_func_t- Pointer to a function to compresses a chunk + * of a WIM resource. This may be either + * wimlib_xpress_compress() (xpress-compress.c) or + * wimlib_lzx_compress() (lzx-compress.c). + * + * @chunk: Uncompressed data of the chunk. + * @chunk_size: Size of the uncompressed chunk, in bytes. + * @out: Pointer to output buffer of size at least (@chunk_size - 1) bytes. + * + * Returns the size of the compressed data written to @out in bytes, or 0 if the + * data could not be compressed to (@chunk_size - 1) bytes or fewer. + * + * As a special requirement, the compression code is optimized for the WIM + * format and therefore requires (@chunk_size <= 32768). + * + * As another special requirement, the compression code will read up to 8 bytes + * off the end of the @chunk array for performance reasons. The values of these + * bytes will not affect the output of the compression, but the calling code + * must make sure that the buffer holding the uncompressed chunk is actually at + * least (@chunk_size + 8) bytes, or at least that these extra bytes are in + * mapped memory that will not cause a memory access violation if accessed. + */ +typedef unsigned (*compress_func_t)(const void *chunk, unsigned chunk_size, + void *out); + +static compress_func_t +get_compress_func(int out_ctype) +{ + if (out_ctype == WIMLIB_COMPRESSION_TYPE_LZX) + return wimlib_lzx_compress; + else + return wimlib_xpress_compress; +} + +/* + * Writes a chunk of a WIM resource to an output file. + * + * @chunk: Uncompressed data of the chunk. + * @chunk_size: Size of the chunk (<= WIM_CHUNK_SIZE) + * @out_fd: File descriptor to write the chunk to. + * @compress: Compression function to use (NULL if writing uncompressed + * data). + * @chunk_tab: Pointer to chunk table being created. It is updated with the + * offset of the chunk we write. + * + * Returns 0 on success; nonzero on failure. + */ +static int +write_wim_resource_chunk(const void * restrict chunk, + unsigned chunk_size, + int out_fd, + compress_func_t compress, + struct chunk_table * restrict chunk_tab) +{ + const void *out_chunk; + unsigned out_chunk_size; + if (compress) { + void *compressed_chunk = alloca(chunk_size); + + out_chunk_size = (*compress)(chunk, chunk_size, compressed_chunk); + if (out_chunk_size) { + /* Write compressed */ + out_chunk = compressed_chunk; + } else { + /* Write uncompressed */ + out_chunk = chunk; + out_chunk_size = chunk_size; + } + chunk_tab_record_chunk(chunk_tab, out_chunk_size); + } else { + /* Write uncompressed */ + out_chunk = chunk; + out_chunk_size = chunk_size; + } + if (full_write(out_fd, out_chunk, out_chunk_size) != out_chunk_size) { + ERROR_WITH_ERRNO("Failed to write WIM resource chunk"); + return WIMLIB_ERR_WRITE; } - w->fp = fp; return 0; } +/* + * Finishes a WIM chunk table and writes it to the output file at the correct + * offset. + * + * The final size of the full compressed resource is returned in the + * @compressed_size_p. + */ +static int +finish_wim_resource_chunk_tab(struct chunk_table *chunk_tab, + int out_fd, u64 *compressed_size_p) +{ + size_t bytes_written; + bytes_written = full_pwrite(out_fd, + chunk_tab->offsets + chunk_tab->bytes_per_chunk_entry, + chunk_tab->table_disk_size, + chunk_tab->file_offset); + if (bytes_written != chunk_tab->table_disk_size) { + ERROR_WITH_ERRNO("Failed to write chunk table in compressed " + "file resource"); + return WIMLIB_ERR_WRITE; + } + if (chunk_tab->bytes_per_chunk_entry == 4) + *compressed_size_p = chunk_tab->cur_offset_u32 + chunk_tab->table_disk_size; + else + *compressed_size_p = chunk_tab->cur_offset_u64 + chunk_tab->table_disk_size; + return 0; +} -/* - * Writes a WIM file to the original file that it was read from, overwriting it. +static int +seek_and_truncate(int out_fd, off_t offset) +{ + if (lseek(out_fd, offset, SEEK_SET) == -1 || + ftruncate(out_fd, offset)) + { + ERROR_WITH_ERRNO("Failed to truncate output WIM file"); + return WIMLIB_ERR_WRITE; + } else { + return 0; + } +} + +static int +finalize_and_check_sha1(SHA_CTX * restrict sha_ctx, + struct wim_lookup_table_entry * restrict lte) +{ + u8 md[SHA1_HASH_SIZE]; + sha1_final(md, sha_ctx); + if (lte->unhashed) { + copy_hash(lte->hash, md); + } else if (!hashes_equal(md, lte->hash)) { + ERROR("WIM resource has incorrect hash!"); + if (lte_filename_valid(lte)) { + ERROR("We were reading it from \"%"TS"\"; maybe " + "it changed while we were reading it.", + lte->file_on_disk); + } + return WIMLIB_ERR_INVALID_RESOURCE_HASH; + } + return 0; +} + + +struct write_resource_ctx { + compress_func_t compress; + struct chunk_table *chunk_tab; + int out_fd; + SHA_CTX sha_ctx; + bool doing_sha; +}; + +static int +write_resource_cb(const void *restrict chunk, size_t chunk_size, + void *restrict _ctx) +{ + struct write_resource_ctx *ctx = _ctx; + + if (ctx->doing_sha) + sha1_update(&ctx->sha_ctx, chunk, chunk_size); + return write_wim_resource_chunk(chunk, chunk_size, + ctx->out_fd, ctx->compress, + ctx->chunk_tab); +} + +/* + * Write a resource to an output WIM. + * + * @lte: Lookup table entry for the resource, which could be in another WIM, + * in an external file, or in another location. + * + * @out_fd: File descriptor opened to the output WIM. + * + * @out_ctype: One of the WIMLIB_COMPRESSION_TYPE_* constants to indicate + * which compression algorithm to use. + * + * @out_res_entry: On success, this is filled in with the offset, flags, + * compressed size, and uncompressed size of the resource + * in the output WIM. + * + * @flags: WIMLIB_RESOURCE_FLAG_RECOMPRESS to force data to be recompressed + * even if it could otherwise be copied directly from the input. + * + * Additional notes: The SHA1 message digest of the uncompressed data is + * calculated (except when doing a raw copy --- see below). If the @unhashed + * flag is set on the lookup table entry, this message digest is simply copied + * to it; otherwise, the message digest is compared with the existing one, and + * the function will fail if they do not match. */ -WIMLIBAPI int wimlib_overwrite(WIMStruct *w, int flags) +int +write_wim_resource(struct wim_lookup_table_entry *lte, + int out_fd, int out_ctype, + struct resource_entry *out_res_entry, + int flags) { - const char *wimfile_name; - size_t wim_name_len; + struct write_resource_ctx write_ctx; + u64 read_size; + u64 new_size; + off_t offset; int ret; - - if (!w) - return WIMLIB_ERR_INVALID_PARAM; - wimfile_name = w->filename; + flags &= ~WIMLIB_RESOURCE_FLAG_RECOMPRESS; - DEBUG("Replacing WIM file `%s'.", wimfile_name); + /* Get current position in output WIM */ + offset = filedes_offset(out_fd); + if (offset == -1) { + ERROR_WITH_ERRNO("Can't get position in output WIM"); + return WIMLIB_ERR_WRITE; + } - if (!wimfile_name) - return WIMLIB_ERR_NO_FILENAME; + /* If we are not forcing the data to be recompressed, and the input + * resource is located in a WIM with the same compression type as that + * desired other than no compression, we can simply copy the compressed + * data without recompressing it. This also means we must skip + * calculating the SHA1, as we never will see the uncompressed data. */ + if (!(flags & WIMLIB_RESOURCE_FLAG_RECOMPRESS) && + lte->resource_location == RESOURCE_IN_WIM && + out_ctype != WIMLIB_COMPRESSION_TYPE_NONE && + wimlib_get_compression_type(lte->wim) == out_ctype) + { + flags |= WIMLIB_RESOURCE_FLAG_RAW; + write_ctx.doing_sha = false; + read_size = lte->resource_entry.size; + } else { + write_ctx.doing_sha = true; + sha1_init(&write_ctx.sha_ctx); + read_size = lte->resource_entry.original_size; + } - /* Write the WIM to a temporary file. */ - /* XXX should the temporary file be somewhere else? */ - wim_name_len = strlen(wimfile_name); - char tmpfile[wim_name_len + 10]; - memcpy(tmpfile, wimfile_name, wim_name_len); - randomize_char_array_with_alnum(tmpfile + wim_name_len, 9); - tmpfile[wim_name_len + 9] = '\0'; + /* Initialize the chunk table and set the compression function if + * compressing the resource. */ + if (out_ctype == WIMLIB_COMPRESSION_TYPE_NONE || + (flags & WIMLIB_RESOURCE_FLAG_RAW)) { + write_ctx.compress = NULL; + write_ctx.chunk_tab = NULL; + } else { + write_ctx.compress = get_compress_func(out_ctype); + ret = begin_wim_resource_chunk_tab(lte, out_fd, + offset, + &write_ctx.chunk_tab); + if (ret) + return ret; + } - ret = wimlib_write(w, tmpfile, WIM_ALL_IMAGES, flags); - if (ret != 0) { - ERROR("Failed to write the WIM file `%s'", tmpfile); - return ret; + /* Write the entire resource by reading the entire resource and feeding + * the data through the write_resource_cb function. */ + write_ctx.out_fd = out_fd; +try_write_again: + ret = read_resource_prefix(lte, read_size, + write_resource_cb, &write_ctx, flags); + if (ret) + goto out_free_chunk_tab; + + /* Verify SHA1 message digest of the resource, or set the hash for the + * first time. */ + if (write_ctx.doing_sha) { + ret = finalize_and_check_sha1(&write_ctx.sha_ctx, lte); + if (ret) + goto out_free_chunk_tab; } - DEBUG("Closing original WIM file."); - /* Close the original WIM file that was opened for reading. */ - if (w->fp) { - if (fclose(w->fp) != 0) { - WARNING("Failed to close the file `%s'", wimfile_name); + out_res_entry->flags = lte->resource_entry.flags; + out_res_entry->original_size = wim_resource_size(lte); + out_res_entry->offset = offset; + if (flags & WIMLIB_RESOURCE_FLAG_RAW) { + /* Doing a raw write: The new compressed size is the same as + * the compressed size in the other WIM. */ + new_size = lte->resource_entry.size; + } else if (out_ctype == WIMLIB_COMPRESSION_TYPE_NONE) { + /* Using WIMLIB_COMPRESSION_TYPE_NONE: The new compressed size + * is the original size. */ + new_size = lte->resource_entry.original_size; + out_res_entry->flags &= ~WIM_RESHDR_FLAG_COMPRESSED; + } else { + /* Using a different compression type: Call + * finish_wim_resource_chunk_tab() and it will provide the new + * compressed size. */ + ret = finish_wim_resource_chunk_tab(write_ctx.chunk_tab, out_fd, + &new_size); + if (ret) + goto out_free_chunk_tab; + if (new_size >= wim_resource_size(lte)) { + /* Oops! We compressed the resource to larger than the original + * size. Write the resource uncompressed instead. */ + DEBUG("Compressed %"PRIu64" => %"PRIu64" bytes; " + "writing uncompressed instead", + wim_resource_size(lte), new_size); + ret = seek_and_truncate(out_fd, offset); + if (ret) + goto out_free_chunk_tab; + write_ctx.compress = NULL; + write_ctx.doing_sha = false; + out_ctype = WIMLIB_COMPRESSION_TYPE_NONE; + goto try_write_again; } - w->fp = NULL; + out_res_entry->flags |= WIM_RESHDR_FLAG_COMPRESSED; + } + out_res_entry->size = new_size; + ret = 0; +out_free_chunk_tab: + FREE(write_ctx.chunk_tab); + return ret; +} + +#ifdef ENABLE_MULTITHREADED_COMPRESSION + +/* Blocking shared queue (solves the producer-consumer problem) */ +struct shared_queue { + unsigned size; + unsigned front; + unsigned back; + unsigned filled_slots; + void **array; + pthread_mutex_t lock; + pthread_cond_t msg_avail_cond; + pthread_cond_t space_avail_cond; +}; + +static int +shared_queue_init(struct shared_queue *q, unsigned size) +{ + wimlib_assert(size != 0); + q->array = CALLOC(sizeof(q->array[0]), size); + if (!q->array) + goto err; + q->filled_slots = 0; + q->front = 0; + q->back = size - 1; + q->size = size; + if (pthread_mutex_init(&q->lock, NULL)) { + ERROR_WITH_ERRNO("Failed to initialize mutex"); + goto err; } + if (pthread_cond_init(&q->msg_avail_cond, NULL)) { + ERROR_WITH_ERRNO("Failed to initialize condition variable"); + goto err_destroy_lock; + } + if (pthread_cond_init(&q->space_avail_cond, NULL)) { + ERROR_WITH_ERRNO("Failed to initialize condition variable"); + goto err_destroy_msg_avail_cond; + } + return 0; +err_destroy_msg_avail_cond: + pthread_cond_destroy(&q->msg_avail_cond); +err_destroy_lock: + pthread_mutex_destroy(&q->lock); +err: + return WIMLIB_ERR_NOMEM; +} - DEBUG("Renaming `%s' to `%s'", tmpfile, wimfile_name); +static void +shared_queue_destroy(struct shared_queue *q) +{ + FREE(q->array); + pthread_mutex_destroy(&q->lock); + pthread_cond_destroy(&q->msg_avail_cond); + pthread_cond_destroy(&q->space_avail_cond); +} - /* Rename the new file to the old file .*/ - if (rename(tmpfile, wimfile_name) != 0) { - ERROR_WITH_ERRNO("Failed to rename `%s' to `%s'", - tmpfile, wimfile_name); - /* Remove temporary file. */ - if (unlink(tmpfile) != 0) - ERROR_WITH_ERRNO("Failed to remove `%s'", tmpfile); - return WIMLIB_ERR_RENAME; +static void +shared_queue_put(struct shared_queue *q, void *obj) +{ + pthread_mutex_lock(&q->lock); + while (q->filled_slots == q->size) + pthread_cond_wait(&q->space_avail_cond, &q->lock); + + q->back = (q->back + 1) % q->size; + q->array[q->back] = obj; + q->filled_slots++; + + pthread_cond_broadcast(&q->msg_avail_cond); + pthread_mutex_unlock(&q->lock); +} + +static void * +shared_queue_get(struct shared_queue *q) +{ + void *obj; + + pthread_mutex_lock(&q->lock); + while (q->filled_slots == 0) + pthread_cond_wait(&q->msg_avail_cond, &q->lock); + + obj = q->array[q->front]; + q->array[q->front] = NULL; + q->front = (q->front + 1) % q->size; + q->filled_slots--; + + pthread_cond_broadcast(&q->space_avail_cond); + pthread_mutex_unlock(&q->lock); + return obj; +} + +struct compressor_thread_params { + struct shared_queue *res_to_compress_queue; + struct shared_queue *compressed_res_queue; + compress_func_t compress; +}; + +#define MAX_CHUNKS_PER_MSG 2 + +struct message { + struct wim_lookup_table_entry *lte; + u8 *uncompressed_chunks[MAX_CHUNKS_PER_MSG]; + u8 *compressed_chunks[MAX_CHUNKS_PER_MSG]; + unsigned uncompressed_chunk_sizes[MAX_CHUNKS_PER_MSG]; + struct iovec out_chunks[MAX_CHUNKS_PER_MSG]; + size_t total_out_bytes; + unsigned num_chunks; + struct list_head list; + bool complete; + u64 begin_chunk; +}; + +static void +compress_chunks(struct message *msg, compress_func_t compress) +{ + msg->total_out_bytes = 0; + for (unsigned i = 0; i < msg->num_chunks; i++) { + unsigned len = compress(msg->uncompressed_chunks[i], + msg->uncompressed_chunk_sizes[i], + msg->compressed_chunks[i]); + void *out_chunk; + unsigned out_len; + if (len) { + /* To be written compressed */ + out_chunk = msg->compressed_chunks[i]; + out_len = len; + } else { + /* To be written uncompressed */ + out_chunk = msg->uncompressed_chunks[i]; + out_len = msg->uncompressed_chunk_sizes[i]; + } + msg->out_chunks[i].iov_base = out_chunk; + msg->out_chunks[i].iov_len = out_len; + msg->total_out_bytes += out_len; } +} - return 0; +/* Compressor thread routine. This is a lot simpler than the main thread + * routine: just repeatedly get a group of chunks from the + * res_to_compress_queue, compress them, and put them in the + * compressed_res_queue. A NULL pointer indicates that the thread should stop. + * */ +static void * +compressor_thread_proc(void *arg) +{ + struct compressor_thread_params *params = arg; + struct shared_queue *res_to_compress_queue = params->res_to_compress_queue; + struct shared_queue *compressed_res_queue = params->compressed_res_queue; + compress_func_t compress = params->compress; + struct message *msg; + + DEBUG("Compressor thread ready"); + while ((msg = shared_queue_get(res_to_compress_queue)) != NULL) { + compress_chunks(msg, compress); + shared_queue_put(compressed_res_queue, msg); + } + DEBUG("Compressor thread terminating"); + return NULL; } +#endif /* ENABLE_MULTITHREADED_COMPRESSION */ +static void +do_write_streams_progress(union wimlib_progress_info *progress, + wimlib_progress_func_t progress_func, + uint64_t size_added, + bool stream_discarded) +{ + if (stream_discarded) { + progress->write_streams.total_bytes -= size_added; + if (progress->write_streams._private != ~(uint64_t)0 && + progress->write_streams._private > progress->write_streams.total_bytes) + { + progress->write_streams._private = progress->write_streams.total_bytes; + } + } else { + progress->write_streams.completed_bytes += size_added; + } + progress->write_streams.completed_streams++; + if (progress_func && + progress->write_streams.completed_bytes >= progress->write_streams._private) + { + progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, + progress); + if (progress->write_streams._private == progress->write_streams.total_bytes) { + progress->write_streams._private = ~(uint64_t)0; + } else { + progress->write_streams._private = + min(progress->write_streams.total_bytes, + progress->write_streams.completed_bytes + + progress->write_streams.total_bytes / 100); + } + } +} + +struct serial_write_stream_ctx { + int out_fd; + int out_ctype; + int write_resource_flags; +}; -WIMLIBAPI int wimlib_overwrite_xml_and_header(WIMStruct *w, int flags) +static int +serial_write_stream(struct wim_lookup_table_entry *lte, void *_ctx) { - int ret; - FILE *fp; - u8 *integrity_table = NULL; - off_t xml_end; - off_t xml_size; - size_t bytes_written; + struct serial_write_stream_ctx *ctx = _ctx; + return write_wim_resource(lte, ctx->out_fd, + ctx->out_ctype, <e->output_resource_entry, + ctx->write_resource_flags); +} - DEBUG("Overwriting XML and header of `%s', flags = %d", - w->filename, flags); - if (!w->filename) - return WIMLIB_ERR_NO_FILENAME; +/* Write a list of streams, taking into account that some streams may be + * duplicates that are checksummed and discarded on the fly, and also delegating + * the actual writing of a stream to a function @write_stream_cb, which is + * passed the context @write_stream_ctx. */ +static int +do_write_stream_list(struct list_head *stream_list, + struct wim_lookup_table *lookup_table, + int (*write_stream_cb)(struct wim_lookup_table_entry *, void *), + void *write_stream_ctx, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress) +{ + int ret = 0; + struct wim_lookup_table_entry *lte; + bool stream_discarded; + + /* For each stream in @stream_list ... */ + while (!list_empty(stream_list)) { + stream_discarded = false; + lte = container_of(stream_list->next, + struct wim_lookup_table_entry, + write_streams_list); + list_del(<e->write_streams_list); + if (lte->unhashed && !lte->unique_size) { + /* Unhashed stream that shares a size with some other + * stream in the WIM we are writing. The stream must be + * checksummed to know if we need to write it or not. */ + struct wim_lookup_table_entry *tmp; + u32 orig_refcnt = lte->out_refcnt; + + ret = hash_unhashed_stream(lte, lookup_table, &tmp); + if (ret) + break; + if (tmp != lte) { + lte = tmp; + /* We found a duplicate stream. */ + if (orig_refcnt != tmp->out_refcnt) { + /* We have already written, or are going + * to write, the duplicate stream. So + * just skip to the next stream. */ + DEBUG("Discarding duplicate stream of length %"PRIu64, + wim_resource_size(lte)); + lte->no_progress = 0; + stream_discarded = true; + goto skip_to_progress; + } + } + } - ret = reopen_rw(w); - if (ret != 0) - return ret; + /* Here, @lte is either a hashed stream or an unhashed stream + * with a unique size. In either case we know that the stream + * has to be written. In either case the SHA1 message digest + * will be calculated over the stream while writing it; however, + * in the former case this is done merely to check the data, + * while in the latter case this is done because we do not have + * the SHA1 message digest yet. */ + wimlib_assert(lte->out_refcnt != 0); + lte->deferred = 0; + lte->no_progress = 0; + ret = (*write_stream_cb)(lte, write_stream_ctx); + if (ret) + break; + /* In parallel mode, some streams are deferred for later, + * serialized processing; ignore them here. */ + if (lte->deferred) + continue; + if (lte->unhashed) { + list_del(<e->unhashed_list); + lookup_table_insert(lookup_table, lte); + lte->unhashed = 0; + } + skip_to_progress: + if (!lte->no_progress) { + do_write_streams_progress(progress, + progress_func, + wim_resource_size(lte), + stream_discarded); + } + } + return ret; +} - fp = w->fp; +static int +do_write_stream_list_serial(struct list_head *stream_list, + struct wim_lookup_table *lookup_table, + int out_fd, + int out_ctype, + int write_resource_flags, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress) +{ + struct serial_write_stream_ctx ctx = { + .out_fd = out_fd, + .out_ctype = out_ctype, + .write_resource_flags = write_resource_flags, + }; + return do_write_stream_list(stream_list, + lookup_table, + serial_write_stream, + &ctx, + progress_func, + progress); +} - /* The old integrity table is still OK, as the SHA1 message digests in - * the integrity table include neither the header nor the XML data. - * Save it for later if it exists and an integrity table was required. - * */ - if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY && - w->hdr.integrity.offset != 0) { - DEBUG("Reading existing integrity table."); - integrity_table = MALLOC(w->hdr.integrity.size); - if (!integrity_table) +static inline int +write_flags_to_resource_flags(int write_flags) +{ + int resource_flags = 0; + + if (write_flags & WIMLIB_WRITE_FLAG_RECOMPRESS) + resource_flags |= WIMLIB_RESOURCE_FLAG_RECOMPRESS; + return resource_flags; +} + +static int +write_stream_list_serial(struct list_head *stream_list, + struct wim_lookup_table *lookup_table, + int out_fd, + int out_ctype, + int write_resource_flags, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress) +{ + DEBUG("Writing stream list (serial version)"); + progress->write_streams.num_threads = 1; + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); + return do_write_stream_list_serial(stream_list, + lookup_table, + out_fd, + out_ctype, + write_resource_flags, + progress_func, + progress); +} + +#ifdef ENABLE_MULTITHREADED_COMPRESSION +static int +write_wim_chunks(struct message *msg, int out_fd, + struct chunk_table *chunk_tab) +{ + for (unsigned i = 0; i < msg->num_chunks; i++) + chunk_tab_record_chunk(chunk_tab, msg->out_chunks[i].iov_len); + if (full_writev(out_fd, msg->out_chunks, + msg->num_chunks) != msg->total_out_bytes) + { + ERROR_WITH_ERRNO("Failed to write WIM chunks"); + return WIMLIB_ERR_WRITE; + } + return 0; +} + +struct main_writer_thread_ctx { + struct list_head *stream_list; + struct wim_lookup_table *lookup_table; + int out_fd; + int out_ctype; + int write_resource_flags; + struct shared_queue *res_to_compress_queue; + struct shared_queue *compressed_res_queue; + size_t num_messages; + wimlib_progress_func_t progress_func; + union wimlib_progress_info *progress; + + struct list_head available_msgs; + struct list_head outstanding_streams; + struct list_head serial_streams; + size_t num_outstanding_messages; + + SHA_CTX next_sha_ctx; + u64 next_chunk; + u64 next_num_chunks; + struct wim_lookup_table_entry *next_lte; + + struct message *msgs; + struct message *next_msg; + struct chunk_table *cur_chunk_tab; +}; + +static int +init_message(struct message *msg) +{ + for (size_t i = 0; i < MAX_CHUNKS_PER_MSG; i++) { + msg->compressed_chunks[i] = MALLOC(WIM_CHUNK_SIZE); + msg->uncompressed_chunks[i] = MALLOC(WIM_CHUNK_SIZE); + if (msg->compressed_chunks[i] == NULL || + msg->uncompressed_chunks[i] == NULL) return WIMLIB_ERR_NOMEM; + } + return 0; +} - ret = read_uncompressed_resource(fp, w->hdr.integrity.offset, - w->hdr.integrity.original_size, - integrity_table); - if (ret != 0) - goto err; - DEBUG("Done reading existing integrity table."); +static void +destroy_message(struct message *msg) +{ + for (size_t i = 0; i < MAX_CHUNKS_PER_MSG; i++) { + FREE(msg->compressed_chunks[i]); + FREE(msg->uncompressed_chunks[i]); } +} - DEBUG("Overwriting XML data."); - /* Overwrite the XML data. */ - if (fseeko(fp, w->hdr.xml_res_entry.offset, SEEK_SET) != 0) { - ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" " - "for XML data", w->hdr.xml_res_entry.offset); - ret = WIMLIB_ERR_WRITE; - goto err; +static void +free_messages(struct message *msgs, size_t num_messages) +{ + if (msgs) { + for (size_t i = 0; i < num_messages; i++) + destroy_message(&msgs[i]); + FREE(msgs); } - ret = write_xml_data(w->wim_info, WIM_ALL_IMAGES, fp, 0); - if (ret != 0) - goto err; +} - DEBUG("Updating XML resource entry."); - /* Update the XML resource entry in the WIM header. */ - xml_end = ftello(fp); - if (xml_end == -1) { - ret = WIMLIB_ERR_WRITE; - goto err; +static struct message * +allocate_messages(size_t num_messages) +{ + struct message *msgs; + + msgs = CALLOC(num_messages, sizeof(struct message)); + if (!msgs) + return NULL; + for (size_t i = 0; i < num_messages; i++) { + if (init_message(&msgs[i])) { + free_messages(msgs, num_messages); + return NULL; + } } - xml_size = xml_end - w->hdr.xml_res_entry.offset; - w->hdr.xml_res_entry.size = xml_size; - w->hdr.xml_res_entry.original_size = xml_size; - - if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) { - DEBUG("Writing integrity table."); - w->hdr.integrity.offset = xml_end; - if (integrity_table) { - /* The existing integrity table was saved. */ - bytes_written = fwrite(integrity_table, 1, - w->hdr.integrity.size, fp); - if (bytes_written != w->hdr.integrity.size) { - ERROR_WITH_ERRNO("Failed to write integrity " - "table"); - ret = WIMLIB_ERR_WRITE; - goto err; + return msgs; +} + +static void +main_writer_thread_destroy_ctx(struct main_writer_thread_ctx *ctx) +{ + while (ctx->num_outstanding_messages--) + shared_queue_get(ctx->compressed_res_queue); + free_messages(ctx->msgs, ctx->num_messages); + FREE(ctx->cur_chunk_tab); +} + +static int +main_writer_thread_init_ctx(struct main_writer_thread_ctx *ctx) +{ + /* Pre-allocate all the buffers that will be needed to do the chunk + * compression. */ + ctx->msgs = allocate_messages(ctx->num_messages); + if (!ctx->msgs) + return WIMLIB_ERR_NOMEM; + + /* Initially, all the messages are available to use. */ + INIT_LIST_HEAD(&ctx->available_msgs); + for (size_t i = 0; i < ctx->num_messages; i++) + list_add_tail(&ctx->msgs[i].list, &ctx->available_msgs); + + /* outstanding_streams is the list of streams that currently have had + * chunks sent off for compression. + * + * The first stream in outstanding_streams is the stream that is + * currently being written. + * + * The last stream in outstanding_streams is the stream that is + * currently being read and having chunks fed to the compressor threads. + * */ + INIT_LIST_HEAD(&ctx->outstanding_streams); + ctx->num_outstanding_messages = 0; + + ctx->next_msg = NULL; + + /* Resources that don't need any chunks compressed are added to this + * list and written directly by the main thread. */ + INIT_LIST_HEAD(&ctx->serial_streams); + + ctx->cur_chunk_tab = NULL; + + return 0; +} + +static int +receive_compressed_chunks(struct main_writer_thread_ctx *ctx) +{ + struct message *msg; + struct wim_lookup_table_entry *cur_lte; + int ret; + + wimlib_assert(!list_empty(&ctx->outstanding_streams)); + wimlib_assert(ctx->num_outstanding_messages != 0); + + cur_lte = container_of(ctx->outstanding_streams.next, + struct wim_lookup_table_entry, + being_compressed_list); + + /* Get the next message from the queue and process it. + * The message will contain 1 or more data chunks that have been + * compressed. */ + msg = shared_queue_get(ctx->compressed_res_queue); + msg->complete = true; + --ctx->num_outstanding_messages; + + /* Is this the next chunk in the current resource? If it's not + * (i.e., an earlier chunk in a same or different resource + * hasn't been compressed yet), do nothing, and keep this + * message around until all earlier chunks are received. + * + * Otherwise, write all the chunks we can. */ + while (cur_lte != NULL && + !list_empty(&cur_lte->msg_list) + && (msg = container_of(cur_lte->msg_list.next, + struct message, + list))->complete) + { + list_move(&msg->list, &ctx->available_msgs); + if (msg->begin_chunk == 0) { + /* This is the first set of chunks. Leave space + * for the chunk table in the output file. */ + off_t cur_offset = filedes_offset(ctx->out_fd); + if (cur_offset == -1) + return WIMLIB_ERR_WRITE; + ret = begin_wim_resource_chunk_tab(cur_lte, + ctx->out_fd, + cur_offset, + &ctx->cur_chunk_tab); + if (ret) + return ret; + } + + /* Write the compressed chunks from the message. */ + ret = write_wim_chunks(msg, ctx->out_fd, ctx->cur_chunk_tab); + if (ret) + return ret; + + /* Was this the last chunk of the stream? If so, finish + * it. */ + if (list_empty(&cur_lte->msg_list) && + msg->begin_chunk + msg->num_chunks == ctx->cur_chunk_tab->num_chunks) + { + u64 res_csize; + off_t offset; + + ret = finish_wim_resource_chunk_tab(ctx->cur_chunk_tab, + ctx->out_fd, + &res_csize); + if (ret) + return ret; + + list_del(&cur_lte->being_compressed_list); + + /* Grab the offset of this stream in the output file + * from the chunk table before we free it. */ + offset = ctx->cur_chunk_tab->file_offset; + + FREE(ctx->cur_chunk_tab); + ctx->cur_chunk_tab = NULL; + + if (res_csize >= wim_resource_size(cur_lte)) { + /* Oops! We compressed the resource to + * larger than the original size. Write + * the resource uncompressed instead. */ + DEBUG("Compressed %"PRIu64" => %"PRIu64" bytes; " + "writing uncompressed instead", + wim_resource_size(cur_lte), res_csize); + ret = seek_and_truncate(ctx->out_fd, offset); + if (ret) + return ret; + ret = write_wim_resource(cur_lte, + ctx->out_fd, + WIMLIB_COMPRESSION_TYPE_NONE, + &cur_lte->output_resource_entry, + ctx->write_resource_flags); + if (ret) + return ret; + } else { + cur_lte->output_resource_entry.size = + res_csize; + + cur_lte->output_resource_entry.original_size = + cur_lte->resource_entry.original_size; + + cur_lte->output_resource_entry.offset = + offset; + + cur_lte->output_resource_entry.flags = + cur_lte->resource_entry.flags | + WIM_RESHDR_FLAG_COMPRESSED; + } + + do_write_streams_progress(ctx->progress, + ctx->progress_func, + wim_resource_size(cur_lte), + false); + + /* Since we just finished writing a stream, write any + * streams that have been added to the serial_streams + * list for direct writing by the main thread (e.g. + * resources that don't need to be compressed because + * the desired compression type is the same as the + * previous compression type). */ + if (!list_empty(&ctx->serial_streams)) { + ret = do_write_stream_list_serial(&ctx->serial_streams, + ctx->lookup_table, + ctx->out_fd, + ctx->out_ctype, + ctx->write_resource_flags, + ctx->progress_func, + ctx->progress); + if (ret) + return ret; + } + + /* Advance to the next stream to write. */ + if (list_empty(&ctx->outstanding_streams)) { + cur_lte = NULL; + } else { + cur_lte = container_of(ctx->outstanding_streams.next, + struct wim_lookup_table_entry, + being_compressed_list); } - FREE(integrity_table); - } else { - /* There was no existing integrity table, so a new one - * must be calculated. */ - ret = write_integrity_table(fp, WIM_HEADER_DISK_SIZE, - w->hdr.lookup_table_res_entry.offset + - w->hdr.lookup_table_res_entry.size, - flags & WIMLIB_WRITE_FLAG_SHOW_PROGRESS); - if (ret != 0) - goto err; - - off_t integrity_size = ftello(fp) - xml_end; - w->hdr.integrity.size = integrity_size; - w->hdr.integrity.original_size = integrity_size; - w->hdr.integrity.flags = 0; } - } else { - DEBUG("Truncating file to end of XML data."); - /* No integrity table to write. The file should be truncated - * because it's possible that the old file was longer (due to it - * including an integrity table, or due to its XML data being - * longer) */ - if (fflush(fp) != 0) { - ERROR_WITH_ERRNO("Failed to flush stream for file `%s'", - w->filename); - return WIMLIB_ERR_WRITE; + } + return 0; +} + +/* Called when the main thread has read a new chunk of data. */ +static int +main_writer_thread_cb(const void *chunk, size_t chunk_size, void *_ctx) +{ + struct main_writer_thread_ctx *ctx = _ctx; + int ret; + struct message *next_msg; + u64 next_chunk_in_msg; + + /* Update SHA1 message digest for the stream currently being read by the + * main thread. */ + sha1_update(&ctx->next_sha_ctx, chunk, chunk_size); + + /* We send chunks of data to the compressor chunks in batches which we + * refer to as "messages". @next_msg is the message that is currently + * being prepared to send off. If it is NULL, that indicates that we + * need to start a new message. */ + next_msg = ctx->next_msg; + if (!next_msg) { + /* We need to start a new message. First check to see if there + * is a message available in the list of available messages. If + * so, we can just take one. If not, all the messages (there is + * a fixed number of them, proportional to the number of + * threads) have been sent off to the compressor threads, so we + * receive messages from the compressor threads containing + * compressed chunks of data. + * + * We may need to receive multiple messages before one is + * actually available to use because messages received that are + * *not* for the very next set of chunks to compress must be + * buffered until it's time to write those chunks. */ + while (list_empty(&ctx->available_msgs)) { + ret = receive_compressed_chunks(ctx); + if (ret) + return ret; } - if (ftruncate(fileno(fp), xml_end) != 0) { - ERROR_WITH_ERRNO("Failed to truncate `%s' to %"PRIu64" " - "bytes", w->filename, xml_end); - return WIMLIB_ERR_WRITE; + + next_msg = container_of(ctx->available_msgs.next, + struct message, list); + list_del(&next_msg->list); + next_msg->complete = false; + next_msg->begin_chunk = ctx->next_chunk; + next_msg->num_chunks = min(MAX_CHUNKS_PER_MSG, + ctx->next_num_chunks - ctx->next_chunk); + ctx->next_msg = next_msg; + } + + /* Fill in the next chunk to compress */ + next_chunk_in_msg = ctx->next_chunk - next_msg->begin_chunk; + + next_msg->uncompressed_chunk_sizes[next_chunk_in_msg] = chunk_size; + memcpy(next_msg->uncompressed_chunks[next_chunk_in_msg], + chunk, chunk_size); + ctx->next_chunk++; + if (++next_chunk_in_msg == next_msg->num_chunks) { + /* Send off an array of chunks to compress */ + list_add_tail(&next_msg->list, &ctx->next_lte->msg_list); + shared_queue_put(ctx->res_to_compress_queue, next_msg); + ++ctx->num_outstanding_messages; + ctx->next_msg = NULL; + } + return 0; +} + +static int +main_writer_thread_finish(void *_ctx) +{ + struct main_writer_thread_ctx *ctx = _ctx; + int ret; + while (ctx->num_outstanding_messages != 0) { + ret = receive_compressed_chunks(ctx); + if (ret) + return ret; + } + wimlib_assert(list_empty(&ctx->outstanding_streams)); + return do_write_stream_list_serial(&ctx->serial_streams, + ctx->lookup_table, + ctx->out_fd, + ctx->out_ctype, + ctx->write_resource_flags, + ctx->progress_func, + ctx->progress); +} + +static int +submit_stream_for_compression(struct wim_lookup_table_entry *lte, + struct main_writer_thread_ctx *ctx) +{ + int ret; + + /* Read the entire stream @lte, feeding its data chunks to the + * compressor threads. Also SHA1-sum the stream; this is required in + * the case that @lte is unhashed, and a nice additional verification + * when @lte is already hashed. */ + sha1_init(&ctx->next_sha_ctx); + ctx->next_chunk = 0; + ctx->next_num_chunks = wim_resource_chunks(lte); + ctx->next_lte = lte; + INIT_LIST_HEAD(<e->msg_list); + list_add_tail(<e->being_compressed_list, &ctx->outstanding_streams); + ret = read_resource_prefix(lte, wim_resource_size(lte), + main_writer_thread_cb, ctx, 0); + if (ret == 0) { + wimlib_assert(ctx->next_chunk == ctx->next_num_chunks); + ret = finalize_and_check_sha1(&ctx->next_sha_ctx, lte); + } + return ret; +} + +static int +main_thread_process_next_stream(struct wim_lookup_table_entry *lte, void *_ctx) +{ + struct main_writer_thread_ctx *ctx = _ctx; + int ret; + + if (wim_resource_size(lte) < 1000 || + ctx->out_ctype == WIMLIB_COMPRESSION_TYPE_NONE || + (lte->resource_location == RESOURCE_IN_WIM && + !(ctx->write_resource_flags & WIMLIB_RESOURCE_FLAG_RECOMPRESS) && + wimlib_get_compression_type(lte->wim) == ctx->out_ctype)) + { + /* Stream is too small or isn't being compressed. Process it by + * the main thread when we have a chance. We can't necessarily + * process it right here, as the main thread could be in the + * middle of writing a different stream. */ + list_add_tail(<e->write_streams_list, &ctx->serial_streams); + lte->deferred = 1; + ret = 0; + } else { + ret = submit_stream_for_compression(lte, ctx); + } + lte->no_progress = 1; + return ret; +} + +static long +get_default_num_threads(void) +{ +#ifdef __WIN32__ + return win32_get_number_of_processors(); +#else + return sysconf(_SC_NPROCESSORS_ONLN); +#endif +} + +/* Equivalent to write_stream_list_serial(), except this takes a @num_threads + * parameter and will perform compression using that many threads. Falls + * back to write_stream_list_serial() on certain errors, such as a failure to + * create the number of threads requested. + * + * High level description of the algorithm for writing compressed streams in + * parallel: We perform compression on chunks of size WIM_CHUNK_SIZE bytes + * rather than on full files. The currently executing thread becomes the main + * thread and is entirely in charge of reading the data to compress (which may + * be in any location understood by the resource code--- such as in an external + * file being captured, or in another WIM file from which an image is being + * exported) and actually writing the compressed data to the output file. + * Additional threads are "compressor threads" and all execute the + * compressor_thread_proc, where they repeatedly retrieve buffers of data from + * the main thread, compress them, and hand them back to the main thread. + * + * Certain streams, such as streams that do not need to be compressed (e.g. + * input compression type same as output compression type) or streams of very + * small size are placed in a list (main_writer_thread_ctx.serial_list) and + * handled entirely by the main thread at an appropriate time. + * + * At any given point in time, multiple streams may be having chunks compressed + * concurrently. The stream that the main thread is currently *reading* may be + * later in the list that the stream that the main thread is currently + * *writing*. + */ +static int +write_stream_list_parallel(struct list_head *stream_list, + struct wim_lookup_table *lookup_table, + int out_fd, + int out_ctype, + int write_resource_flags, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress, + unsigned num_threads) +{ + int ret; + struct shared_queue res_to_compress_queue; + struct shared_queue compressed_res_queue; + pthread_t *compressor_threads = NULL; + + if (num_threads == 0) { + long nthreads = get_default_num_threads(); + if (nthreads < 1 || nthreads > UINT_MAX) { + WARNING("Could not determine number of processors! Assuming 1"); + goto out_serial; + } else if (nthreads == 1) { + goto out_serial_quiet; + } else { + num_threads = nthreads; } - memset(&w->hdr.integrity, 0, sizeof(struct resource_entry)); } - DEBUG("Overwriting header."); - /* Overwrite the header. */ - if (fseeko(fp, 0, SEEK_SET) != 0) { - ERROR_WITH_ERRNO("Failed to seek to beginning of `%s'", - w->filename); - return WIMLIB_ERR_WRITE; + DEBUG("Writing stream list (parallel version, num_threads=%u)", + num_threads); + + progress->write_streams.num_threads = num_threads; + + static const size_t MESSAGES_PER_THREAD = 2; + size_t queue_size = (size_t)(num_threads * MESSAGES_PER_THREAD); + + DEBUG("Initializing shared queues (queue_size=%zu)", queue_size); + + ret = shared_queue_init(&res_to_compress_queue, queue_size); + if (ret) + goto out_serial; + + ret = shared_queue_init(&compressed_res_queue, queue_size); + if (ret) + goto out_destroy_res_to_compress_queue; + + struct compressor_thread_params params; + params.res_to_compress_queue = &res_to_compress_queue; + params.compressed_res_queue = &compressed_res_queue; + params.compress = get_compress_func(out_ctype); + + compressor_threads = MALLOC(num_threads * sizeof(pthread_t)); + if (!compressor_threads) { + ret = WIMLIB_ERR_NOMEM; + goto out_destroy_compressed_res_queue; + } + + for (unsigned i = 0; i < num_threads; i++) { + DEBUG("pthread_create thread %u of %u", i + 1, num_threads); + ret = pthread_create(&compressor_threads[i], NULL, + compressor_thread_proc, ¶ms); + if (ret != 0) { + ret = -1; + ERROR_WITH_ERRNO("Failed to create compressor " + "thread %u of %u", + i + 1, num_threads); + num_threads = i; + goto out_join; + } } - ret = write_header(&w->hdr, fp); - if (ret != 0) + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); + + struct main_writer_thread_ctx ctx; + ctx.stream_list = stream_list; + ctx.lookup_table = lookup_table; + ctx.out_fd = out_fd; + ctx.out_ctype = out_ctype; + ctx.res_to_compress_queue = &res_to_compress_queue; + ctx.compressed_res_queue = &compressed_res_queue; + ctx.num_messages = queue_size; + ctx.write_resource_flags = write_resource_flags; + ctx.progress_func = progress_func; + ctx.progress = progress; + ret = main_writer_thread_init_ctx(&ctx); + if (ret) + goto out_join; + ret = do_write_stream_list(stream_list, lookup_table, + main_thread_process_next_stream, + &ctx, progress_func, progress); + if (ret) + goto out_destroy_ctx; + + /* The main thread has finished reading all streams that are going to be + * compressed in parallel, and it now needs to wait for all remaining + * chunks to be compressed so that the remaining streams can actually be + * written to the output file. Furthermore, any remaining streams that + * had processing deferred to the main thread need to be handled. These + * tasks are done by the main_writer_thread_finish() function. */ + ret = main_writer_thread_finish(&ctx); +out_destroy_ctx: + main_writer_thread_destroy_ctx(&ctx); +out_join: + for (unsigned i = 0; i < num_threads; i++) + shared_queue_put(&res_to_compress_queue, NULL); + + for (unsigned i = 0; i < num_threads; i++) { + if (pthread_join(compressor_threads[i], NULL)) { + WARNING_WITH_ERRNO("Failed to join compressor " + "thread %u of %u", + i + 1, num_threads); + } + } + FREE(compressor_threads); +out_destroy_compressed_res_queue: + shared_queue_destroy(&compressed_res_queue); +out_destroy_res_to_compress_queue: + shared_queue_destroy(&res_to_compress_queue); + if (ret >= 0 && ret != WIMLIB_ERR_NOMEM) return ret; +out_serial: + WARNING("Falling back to single-threaded compression"); +out_serial_quiet: + return write_stream_list_serial(stream_list, + lookup_table, + out_fd, + out_ctype, + write_resource_flags, + progress_func, + progress); - DEBUG("Closing `%s'.", w->filename); - if (fclose(fp) != 0) { - ERROR_WITH_ERRNO("Failed to close `%s'", w->filename); - return WIMLIB_ERR_WRITE; +} +#endif + +/* + * Write a list of streams to a WIM (@out_fd) using the compression type + * @out_ctype and up to @num_threads compressor threads. + */ +static int +write_stream_list(struct list_head *stream_list, + struct wim_lookup_table *lookup_table, + int out_fd, int out_ctype, int write_flags, + unsigned num_threads, wimlib_progress_func_t progress_func) +{ + struct wim_lookup_table_entry *lte; + size_t num_streams = 0; + u64 total_bytes = 0; + u64 total_compression_bytes = 0; + union wimlib_progress_info progress; + int ret; + int write_resource_flags; + + if (list_empty(stream_list)) + return 0; + + write_resource_flags = write_flags_to_resource_flags(write_flags); + + /* Calculate the total size of the streams to be written. Note: this + * will be the uncompressed size, as we may not know the compressed size + * yet, and also this will assume that every unhashed stream will be + * written (which will not necessarily be the case). */ + list_for_each_entry(lte, stream_list, write_streams_list) { + num_streams++; + total_bytes += wim_resource_size(lte); + if (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE + && (wim_resource_compression_type(lte) != out_ctype || + (write_resource_flags & WIMLIB_RESOURCE_FLAG_RECOMPRESS))) + { + total_compression_bytes += wim_resource_size(lte); + } } - w->fp = NULL; - DEBUG("Done."); - return 0; -err: - FREE(integrity_table); + progress.write_streams.total_bytes = total_bytes; + progress.write_streams.total_streams = num_streams; + progress.write_streams.completed_bytes = 0; + progress.write_streams.completed_streams = 0; + progress.write_streams.num_threads = num_threads; + progress.write_streams.compression_type = out_ctype; + progress.write_streams._private = 0; + +#ifdef ENABLE_MULTITHREADED_COMPRESSION + if (total_compression_bytes >= 2000000 && num_threads != 1) + ret = write_stream_list_parallel(stream_list, + lookup_table, + out_fd, + out_ctype, + write_resource_flags, + progress_func, + &progress, + num_threads); + else +#endif + ret = write_stream_list_serial(stream_list, + lookup_table, + out_fd, + out_ctype, + write_resource_flags, + progress_func, + &progress); return ret; } +struct stream_size_table { + struct hlist_head *array; + size_t num_entries; + size_t capacity; +}; -/* Write the file resources for the current image. */ -static int write_file_resources(WIMStruct *w) +static int +init_stream_size_table(struct stream_size_table *tab, size_t capacity) { + tab->array = CALLOC(capacity, sizeof(tab->array[0])); + if (!tab->array) + return WIMLIB_ERR_NOMEM; + tab->num_entries = 0; + tab->capacity = capacity; + return 0; +} - DEBUG("Writing file resources for image %u.", w->current_image); - return for_dentry_in_tree(wim_root_dentry(w), write_dentry_resources, w); +static void +destroy_stream_size_table(struct stream_size_table *tab) +{ + FREE(tab->array); } -/* Write the lookup table, xml data, and integrity table, then overwrite the WIM - * header. - * - * write_lt is zero iff the lookup table is not to be written; i.e. it is - * handled elsewhere. */ -int finish_write(WIMStruct *w, int image, int flags, int write_lt) +static int +stream_size_table_insert(struct wim_lookup_table_entry *lte, void *_tab) { - off_t lookup_table_offset; - off_t xml_data_offset; - off_t lookup_table_size; - off_t integrity_offset; - off_t xml_data_size; + struct stream_size_table *tab = _tab; + size_t pos; + struct wim_lookup_table_entry *same_size_lte; + struct hlist_node *tmp; + + pos = hash_u64(wim_resource_size(lte)) % tab->capacity; + lte->unique_size = 1; + hlist_for_each_entry(same_size_lte, tmp, &tab->array[pos], hash_list_2) { + if (wim_resource_size(same_size_lte) == wim_resource_size(lte)) { + lte->unique_size = 0; + same_size_lte->unique_size = 0; + break; + } + } + + hlist_add_head(<e->hash_list_2, &tab->array[pos]); + tab->num_entries++; + return 0; +} + + +struct lte_overwrite_prepare_args { + WIMStruct *wim; off_t end_offset; - off_t integrity_size; + struct list_head stream_list; + struct stream_size_table stream_size_tab; +}; + +/* First phase of preparing streams for an in-place overwrite. This is called + * on all streams, both hashed and unhashed, except the metadata resources. */ +static int +lte_overwrite_prepare(struct wim_lookup_table_entry *lte, void *_args) +{ + struct lte_overwrite_prepare_args *args = _args; + + wimlib_assert(!(lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)); + if (lte->resource_location != RESOURCE_IN_WIM || lte->wim != args->wim) + list_add_tail(<e->write_streams_list, &args->stream_list); + lte->out_refcnt = lte->refcnt; + stream_size_table_insert(lte, &args->stream_size_tab); + return 0; +} + +/* Second phase of preparing streams for an in-place overwrite. This is called + * on existing metadata resources and hashed streams, but not unhashed streams. + * + * NOTE: lte->output_resource_entry is in union with lte->hash_list_2, so + * lte_overwrite_prepare_2() must be called after lte_overwrite_prepare(), as + * the latter uses lte->hash_list_2, while the former expects to set + * lte->output_resource_entry. */ +static int +lte_overwrite_prepare_2(struct wim_lookup_table_entry *lte, void *_args) +{ + struct lte_overwrite_prepare_args *args = _args; + + if (lte->resource_location == RESOURCE_IN_WIM && lte->wim == args->wim) { + /* We can't do an in place overwrite on the WIM if there are + * streams after the XML data. */ + if (lte->resource_entry.offset + + lte->resource_entry.size > args->end_offset) + { + #ifdef ENABLE_ERROR_MESSAGES + ERROR("The following resource is after the XML data:"); + print_lookup_table_entry(lte, stderr); + #endif + return WIMLIB_ERR_RESOURCE_ORDER; + } + copy_resource_entry(<e->output_resource_entry, + <e->resource_entry); + } + return 0; +} + +/* Given a WIM that we are going to overwrite in place with zero or more + * additional streams added, construct a list the list of new unique streams + * ('struct wim_lookup_table_entry's) that must be written, plus any unhashed + * streams that need to be added but may be identical to other hashed or + * unhashed streams. These unhashed streams are checksummed while the streams + * are being written. To aid this process, the member @unique_size is set to 1 + * on streams that have a unique size and therefore must be written. + * + * The out_refcnt member of each 'struct wim_lookup_table_entry' is set to + * indicate the number of times the stream is referenced in only the streams + * that are being written; this may still be adjusted later when unhashed + * streams are being resolved. + */ +static int +prepare_streams_for_overwrite(WIMStruct *wim, off_t end_offset, + struct list_head *stream_list) +{ int ret; - struct wim_header hdr; - FILE *out = w->out_fp; + struct lte_overwrite_prepare_args args; + unsigned i; + + args.wim = wim; + args.end_offset = end_offset; + ret = init_stream_size_table(&args.stream_size_tab, + wim->lookup_table->capacity); + if (ret) + return ret; - if (write_lt) { - lookup_table_offset = ftello(out); - if (lookup_table_offset == -1) - return WIMLIB_ERR_WRITE; + INIT_LIST_HEAD(&args.stream_list); + for (i = 0; i < wim->hdr.image_count; i++) { + struct wim_image_metadata *imd; + struct wim_lookup_table_entry *lte; - DEBUG("Writing lookup table (offset %"PRIu64")", lookup_table_offset); - /* Write the lookup table. */ - ret = write_lookup_table(w->lookup_table, out); - if (ret != 0) - return ret; + imd = wim->image_metadata[i]; + image_for_each_unhashed_stream(lte, imd) + lte_overwrite_prepare(lte, &args); + } + for_lookup_table_entry(wim->lookup_table, lte_overwrite_prepare, &args); + list_transfer(&args.stream_list, stream_list); + + for (i = 0; i < wim->hdr.image_count; i++) { + ret = lte_overwrite_prepare_2(wim->image_metadata[i]->metadata_lte, + &args); + if (ret) + goto out_destroy_stream_size_table; } + ret = for_lookup_table_entry(wim->lookup_table, + lte_overwrite_prepare_2, &args); +out_destroy_stream_size_table: + destroy_stream_size_table(&args.stream_size_tab); + return ret; +} - xml_data_offset = ftello(out); - if (xml_data_offset == -1) - return WIMLIB_ERR_WRITE; - DEBUG("Writing XML data (offset %"PRIu64")", xml_data_offset); +struct find_streams_ctx { + struct list_head stream_list; + struct stream_size_table stream_size_tab; +}; + +static void +inode_find_streams_to_write(struct wim_inode *inode, + struct wim_lookup_table *table, + struct list_head *stream_list, + struct stream_size_table *tab) +{ + struct wim_lookup_table_entry *lte; + for (unsigned i = 0; i <= inode->i_num_ads; i++) { + lte = inode_stream_lte(inode, i, table); + if (lte) { + if (lte->out_refcnt == 0) { + if (lte->unhashed) + stream_size_table_insert(lte, tab); + list_add_tail(<e->write_streams_list, stream_list); + } + lte->out_refcnt += inode->i_nlink; + } + } +} + +static int +image_find_streams_to_write(WIMStruct *w) +{ + struct find_streams_ctx *ctx; + struct wim_image_metadata *imd; + struct wim_inode *inode; + struct wim_lookup_table_entry *lte; + + ctx = w->private; + imd = wim_get_current_image_metadata(w); + + image_for_each_unhashed_stream(lte, imd) + lte->out_refcnt = 0; + + /* Go through this image's inodes to find any streams that have not been + * found yet. */ + image_for_each_inode(inode, imd) { + inode_find_streams_to_write(inode, w->lookup_table, + &ctx->stream_list, + &ctx->stream_size_tab); + } + return 0; +} + +/* Given a WIM that from which one or all of the images is being written, build + * the list of unique streams ('struct wim_lookup_table_entry's) that must be + * written, plus any unhashed streams that need to be written but may be + * identical to other hashed or unhashed streams being written. These unhashed + * streams are checksummed while the streams are being written. To aid this + * process, the member @unique_size is set to 1 on streams that have a unique + * size and therefore must be written. + * + * The out_refcnt member of each 'struct wim_lookup_table_entry' is set to + * indicate the number of times the stream is referenced in only the streams + * that are being written; this may still be adjusted later when unhashed + * streams are being resolved. + */ +static int +prepare_stream_list(WIMStruct *wim, int image, struct list_head *stream_list) +{ + int ret; + struct find_streams_ctx ctx; + + for_lookup_table_entry(wim->lookup_table, lte_zero_out_refcnt, NULL); + ret = init_stream_size_table(&ctx.stream_size_tab, + wim->lookup_table->capacity); + if (ret) + return ret; + for_lookup_table_entry(wim->lookup_table, stream_size_table_insert, + &ctx.stream_size_tab); + INIT_LIST_HEAD(&ctx.stream_list); + wim->private = &ctx; + ret = for_image(wim, image, image_find_streams_to_write); + destroy_stream_size_table(&ctx.stream_size_tab); + if (ret == 0) + list_transfer(&ctx.stream_list, stream_list); + return ret; +} + +/* Writes the streams for the specified @image in @wim to @wim->out_fd. + */ +static int +write_wim_streams(WIMStruct *wim, int image, int write_flags, + unsigned num_threads, + wimlib_progress_func_t progress_func) +{ + int ret; + struct list_head stream_list; + + ret = prepare_stream_list(wim, image, &stream_list); + if (ret) + return ret; + return write_stream_list(&stream_list, + wim->lookup_table, + wim->out_fd, + wimlib_get_compression_type(wim), + write_flags, + num_threads, + progress_func); +} + +/* + * Finish writing a WIM file: write the lookup table, xml data, and integrity + * table (optional), then overwrite the WIM header. + * + * write_flags is a bitwise OR of the following: + * + * (public) WIMLIB_WRITE_FLAG_CHECK_INTEGRITY: + * Include an integrity table. + * + * (private) WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE: + * Don't write the lookup table. + * + * (private) WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE: + * When (if) writing the integrity table, re-use entries from the + * existing integrity table, if possible. + * + * (private) WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML: + * After writing the XML data but before writing the integrity + * table, write a temporary WIM header and flush the stream so that + * the WIM is less likely to become corrupted upon abrupt program + * termination. + * + * (private) WIMLIB_WRITE_FLAG_FSYNC: + * fsync() the output file before closing it. + * + */ +int +finish_write(WIMStruct *w, int image, int write_flags, + wimlib_progress_func_t progress_func) +{ + int ret; + struct wim_header hdr; /* @hdr will be the header for the new WIM. First copy all the data * from the header in the WIMStruct; then set all the fields that may * have changed, including the resource entries, boot index, and image * count. */ memcpy(&hdr, &w->hdr, sizeof(struct wim_header)); - if (write_lt) { - lookup_table_size = xml_data_offset - lookup_table_offset; - hdr.lookup_table_res_entry.offset = lookup_table_offset; - hdr.lookup_table_res_entry.size = lookup_table_size; - } - hdr.lookup_table_res_entry.original_size = hdr.lookup_table_res_entry.size; - hdr.lookup_table_res_entry.flags = WIM_RESHDR_FLAG_METADATA; - ret = write_xml_data(w->wim_info, image, out, - write_lt ? 0 : wim_info_get_total_bytes(w->wim_info)); - if (ret != 0) - return ret; - - integrity_offset = ftello(out); - if (integrity_offset == -1) - return WIMLIB_ERR_WRITE; - xml_data_size = integrity_offset - xml_data_offset; - - hdr.xml_res_entry.offset = xml_data_offset; - hdr.xml_res_entry.size = xml_data_size; - hdr.xml_res_entry.original_size = xml_data_size; - hdr.xml_res_entry.flags = 0; - - if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) { - ret = write_integrity_table(out, WIM_HEADER_DISK_SIZE, - xml_data_offset, - flags & WIMLIB_WRITE_FLAG_SHOW_PROGRESS); - if (ret != 0) - return ret; - end_offset = ftello(out); - if (end_offset == -1) - return WIMLIB_ERR_WRITE; - integrity_size = end_offset - integrity_offset; - hdr.integrity.offset = integrity_offset; - hdr.integrity.size = integrity_size; - hdr.integrity.original_size = integrity_size; - } else { - hdr.integrity.offset = 0; - hdr.integrity.size = 0; - hdr.integrity.original_size = 0; + /* Set image count and boot index correctly for single image writes */ + if (image != WIMLIB_ALL_IMAGES) { + hdr.image_count = 1; + if (hdr.boot_idx == image) + hdr.boot_idx = 1; + else + hdr.boot_idx = 0; } - hdr.integrity.flags = 0; - - DEBUG("Updating WIM header."); - /* - * In the WIM header, there is room for the resource entry for a + /* In the WIM header, there is room for the resource entry for a * metadata resource labeled as the "boot metadata". This entry should * be zeroed out if there is no bootable image (boot_idx 0). Otherwise, * it should be a copy of the resource entry for the image that is - * marked as bootable. This is not well documented... - */ - if (hdr.boot_idx == 0 || !w->image_metadata - || (image != WIM_ALL_IMAGES && image != hdr.boot_idx)) { - memset(&hdr.boot_metadata_res_entry, 0, - sizeof(struct resource_entry)); + * marked as bootable. This is not well documented... */ + if (hdr.boot_idx == 0) { + zero_resource_entry(&hdr.boot_metadata_res_entry); } else { - memcpy(&hdr.boot_metadata_res_entry, - &w->image_metadata[ - hdr.boot_idx - 1].metadata_lte->output_resource_entry, - sizeof(struct resource_entry)); + copy_resource_entry(&hdr.boot_metadata_res_entry, + &w->image_metadata[ hdr.boot_idx- 1 + ]->metadata_lte->output_resource_entry); } - /* Set image count and boot index correctly for single image writes */ - if (image != WIM_ALL_IMAGES) { - hdr.image_count = 1; - if (hdr.boot_idx == image) - hdr.boot_idx = 1; - else - hdr.boot_idx = 0; + if (!(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) { + ret = write_lookup_table(w, image, &hdr.lookup_table_res_entry); + if (ret) + goto out_close_wim; } + ret = write_xml_data(w->wim_info, image, w->out_fd, + (write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE) ? + wim_info_get_total_bytes(w->wim_info) : 0, + &hdr.xml_res_entry); + if (ret) + goto out_close_wim; + + if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) { + if (write_flags & WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML) { + struct wim_header checkpoint_hdr; + memcpy(&checkpoint_hdr, &hdr, sizeof(struct wim_header)); + zero_resource_entry(&checkpoint_hdr.integrity); + ret = write_header(&checkpoint_hdr, w->out_fd); + if (ret) + goto out_close_wim; + } - if (fseeko(out, 0, SEEK_SET) != 0) - return WIMLIB_ERR_WRITE; + off_t old_lookup_table_end; + off_t new_lookup_table_end; + if (write_flags & WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE) { + old_lookup_table_end = w->hdr.lookup_table_res_entry.offset + + w->hdr.lookup_table_res_entry.size; + } else { + old_lookup_table_end = 0; + } + new_lookup_table_end = hdr.lookup_table_res_entry.offset + + hdr.lookup_table_res_entry.size; + + ret = write_integrity_table(w->out_fd, + &hdr.integrity, + new_lookup_table_end, + old_lookup_table_end, + progress_func); + if (ret) + goto out_close_wim; + } else { + zero_resource_entry(&hdr.integrity); + } + + ret = write_header(&hdr, w->out_fd); + if (ret) + goto out_close_wim; - return write_header(&hdr, out); + if (write_flags & WIMLIB_WRITE_FLAG_FSYNC) { + if (fsync(w->out_fd)) { + ERROR_WITH_ERRNO("Error syncing data to WIM file"); + ret = WIMLIB_ERR_WRITE; + } + } +out_close_wim: + if (close(w->out_fd)) { + ERROR_WITH_ERRNO("Failed to close the output WIM file"); + if (ret == 0) + ret = WIMLIB_ERR_WRITE; + } + w->out_fd = -1; + return ret; } -/* Open file stream and write dummy header for WIM. */ -int begin_write(WIMStruct *w, const char *path, int flags) +#if defined(HAVE_SYS_FILE_H) && defined(HAVE_FLOCK) +int +lock_wim(WIMStruct *w, int fd) { - const char *mode; - DEBUG("Opening `%s' for new WIM", path); - - /* checking the integrity requires going back over the file to read it. - * XXX - * (It also would be possible to keep a running sha1sum as the file - * as written-- this would be faster, but a bit more complicated) */ - if (flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) - mode = "w+b"; - else - mode = "wb"; + int ret = 0; + if (fd != -1 && !w->wim_locked) { + ret = flock(fd, LOCK_EX | LOCK_NB); + if (ret != 0) { + if (errno == EWOULDBLOCK) { + ERROR("`%"TS"' is already being modified or has been " + "mounted read-write\n" + " by another process!", w->filename); + ret = WIMLIB_ERR_ALREADY_LOCKED; + } else { + WARNING_WITH_ERRNO("Failed to lock `%"TS"'", + w->filename); + ret = 0; + } + } else { + w->wim_locked = 1; + } + } + return ret; +} +#endif - w->out_fp = fopen(path, mode); - if (!w->out_fp) { - ERROR_WITH_ERRNO("Failed to open the file `%s' for writing", - path); +static int +open_wim_writable(WIMStruct *w, const tchar *path, int open_flags) +{ + w->out_fd = topen(path, open_flags | O_BINARY, 0644); + if (w->out_fd == -1) { + ERROR_WITH_ERRNO("Failed to open `%"TS"' for writing", path); return WIMLIB_ERR_OPEN; } + return 0; +} + +void +close_wim_writable(WIMStruct *w) +{ + if (w->out_fd != -1) { + if (close(w->out_fd)) + WARNING_WITH_ERRNO("Failed to close output WIM"); + w->out_fd = -1; + } +} + +/* Open file stream and write dummy header for WIM. */ +int +begin_write(WIMStruct *w, const tchar *path, int write_flags) +{ + int ret; + int open_flags = O_TRUNC | O_CREAT; + if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) + open_flags |= O_RDWR; + else + open_flags |= O_WRONLY; + ret = open_wim_writable(w, path, open_flags); + if (ret) + return ret; /* Write dummy header. It will be overwritten later. */ - return write_header(&w->hdr, w->out_fp); + ret = write_header(&w->hdr, w->out_fd); + if (ret) + return ret; + if (lseek(w->out_fd, WIM_HEADER_DISK_SIZE, SEEK_SET) == -1) { + ERROR_WITH_ERRNO("Failed to seek to end of WIM header"); + return WIMLIB_ERR_WRITE; + } + return 0; } -/* Writes the WIM to a file. */ -WIMLIBAPI int wimlib_write(WIMStruct *w, const char *path, int image, int flags) +/* Writes a stand-alone WIM to a file. */ +WIMLIBAPI int +wimlib_write(WIMStruct *w, const tchar *path, + int image, int write_flags, unsigned num_threads, + wimlib_progress_func_t progress_func) { int ret; - if (!w || !path) + if (!path) return WIMLIB_ERR_INVALID_PARAM; - if (image != WIM_ALL_IMAGES && + write_flags &= WIMLIB_WRITE_MASK_PUBLIC; + + if (image != WIMLIB_ALL_IMAGES && (image < 1 || image > w->hdr.image_count)) return WIMLIB_ERR_INVALID_IMAGE; - if (w->hdr.total_parts != 1) { ERROR("Cannot call wimlib_write() on part of a split WIM"); return WIMLIB_ERR_SPLIT_UNSUPPORTED; } - if (image == WIM_ALL_IMAGES) - DEBUG("Writing all images to `%s'.", path); - else - DEBUG("Writing image %d to `%s'.", image, path); + ret = begin_write(w, path, write_flags); + if (ret) + goto out_close_wim; + + ret = write_wim_streams(w, image, write_flags, num_threads, + progress_func); + if (ret) + goto out_close_wim; - ret = begin_write(w, path, flags); - if (ret != 0) - goto done; + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_BEGIN, NULL); + + ret = for_image(w, image, write_metadata_resource); + if (ret) + goto out_close_wim; + + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_END, NULL); + + ret = finish_write(w, image, write_flags, progress_func); + /* finish_write() closed the WIM for us */ + goto out; +out_close_wim: + close_wim_writable(w); +out: + DEBUG("wimlib_write(path=%"TS") = %d", path, ret); + return ret; +} + +static bool +any_images_modified(WIMStruct *w) +{ + for (int i = 0; i < w->hdr.image_count; i++) + if (w->image_metadata[i]->modified) + return true; + return false; +} - for_lookup_table_entry(w->lookup_table, zero_out_refcnts, NULL); +/* + * Overwrite a WIM, possibly appending streams to it. + * + * A WIM looks like (or is supposed to look like) the following: + * + * Header (212 bytes) + * Streams and metadata resources (variable size) + * Lookup table (variable size) + * XML data (variable size) + * Integrity table (optional) (variable size) + * + * If we are not adding any streams or metadata resources, the lookup table is + * unchanged--- so we only need to overwrite the XML data, integrity table, and + * header. This operation is potentially unsafe if the program is abruptly + * terminated while the XML data or integrity table are being overwritten, but + * before the new header has been written. To partially alleviate this problem, + * a special flag (WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML) is passed to + * finish_write() to cause a temporary WIM header to be written after the XML + * data has been written. This may prevent the WIM from becoming corrupted if + * the program is terminated while the integrity table is being calculated (but + * no guarantees, due to write re-ordering...). + * + * If we are adding new streams or images (metadata resources), the lookup table + * needs to be changed, and those streams need to be written. In this case, we + * try to perform a safe update of the WIM file by writing the streams *after* + * the end of the previous WIM, then writing the new lookup table, XML data, and + * (optionally) integrity table following the new streams. This will produce a + * layout like the following: + * + * Header (212 bytes) + * (OLD) Streams and metadata resources (variable size) + * (OLD) Lookup table (variable size) + * (OLD) XML data (variable size) + * (OLD) Integrity table (optional) (variable size) + * (NEW) Streams and metadata resources (variable size) + * (NEW) Lookup table (variable size) + * (NEW) XML data (variable size) + * (NEW) Integrity table (optional) (variable size) + * + * At all points, the WIM is valid as nothing points to the new data yet. Then, + * the header is overwritten to point to the new lookup table, XML data, and + * integrity table, to produce the following layout: + * + * Header (212 bytes) + * Streams and metadata resources (variable size) + * Nothing (variable size) + * More Streams and metadata resources (variable size) + * Lookup table (variable size) + * XML data (variable size) + * Integrity table (optional) (variable size) + * + * This method allows an image to be appended to a large WIM very quickly, and + * is is crash-safe except in the case of write re-ordering, but the + * disadvantage is that a small hole is left in the WIM where the old lookup + * table, xml data, and integrity table were. (These usually only take up a + * small amount of space compared to the streams, however.) + */ +static int +overwrite_wim_inplace(WIMStruct *w, int write_flags, + unsigned num_threads, + wimlib_progress_func_t progress_func) +{ + int ret; + struct list_head stream_list; + off_t old_wim_end; + u64 old_lookup_table_end, old_xml_begin, old_xml_end; + int open_flags; + + DEBUG("Overwriting `%"TS"' in-place", w->filename); + + /* Make sure that the integrity table (if present) is after the XML + * data, and that there are no stream resources, metadata resources, or + * lookup tables after the XML data. Otherwise, these data would be + * overwritten. */ + old_xml_begin = w->hdr.xml_res_entry.offset; + old_xml_end = old_xml_begin + w->hdr.xml_res_entry.size; + old_lookup_table_end = w->hdr.lookup_table_res_entry.offset + + w->hdr.lookup_table_res_entry.size; + if (w->hdr.integrity.offset != 0 && w->hdr.integrity.offset < old_xml_end) { + ERROR("Didn't expect the integrity table to be before the XML data"); + return WIMLIB_ERR_RESOURCE_ORDER; + } - w->write_flags = flags; + if (old_lookup_table_end > old_xml_begin) { + ERROR("Didn't expect the lookup table to be after the XML data"); + return WIMLIB_ERR_RESOURCE_ORDER; + } - ret = for_image(w, image, write_file_resources); - if (ret != 0) { - ERROR("Failed to write WIM file resources to `%s'", path); - goto done; + /* Set @old_wim_end, which indicates the point beyond which we don't + * allow any file and metadata resources to appear without returning + * WIMLIB_ERR_RESOURCE_ORDER (due to the fact that we would otherwise + * overwrite these resources). */ + if (!w->deletion_occurred && !any_images_modified(w)) { + /* If no images have been modified and no images have been + * deleted, a new lookup table does not need to be written. We + * shall write the new XML data and optional integrity table + * immediately after the lookup table. Note that this may + * overwrite an existing integrity table. */ + DEBUG("Skipping writing lookup table " + "(no images modified or deleted)"); + old_wim_end = old_lookup_table_end; + write_flags |= WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE | + WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML; + } else if (w->hdr.integrity.offset) { + /* Old WIM has an integrity table; begin writing new streams + * after it. */ + old_wim_end = w->hdr.integrity.offset + w->hdr.integrity.size; + } else { + /* No existing integrity table; begin writing new streams after + * the old XML data. */ + old_wim_end = old_xml_end; } - ret = for_image(w, image, write_metadata_resource); + ret = prepare_streams_for_overwrite(w, old_wim_end, &stream_list); + if (ret) + return ret; - if (ret != 0) { - ERROR("Failed to write WIM image metadata to `%s'", path); - goto done; + open_flags = 0; + if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) + open_flags |= O_RDWR; + else + open_flags |= O_WRONLY; + ret = open_wim_writable(w, w->filename, open_flags); + if (ret) + return ret; + + ret = lock_wim(w, w->out_fd); + if (ret) { + close_wim_writable(w); + return ret; } - ret = finish_write(w, image, flags, 1); + if (lseek(w->out_fd, old_wim_end, SEEK_SET) == -1) { + ERROR_WITH_ERRNO("Can't seek to end of WIM"); + close_wim_writable(w); + w->wim_locked = 0; + return WIMLIB_ERR_WRITE; + } -done: - DEBUG("Closing output file."); - if (w->out_fp != NULL) { - if (fclose(w->out_fp) != 0) { - ERROR_WITH_ERRNO("Failed to close the file `%s'", path); - ret = WIMLIB_ERR_WRITE; + DEBUG("Writing newly added streams (offset = %"PRIu64")", + old_wim_end); + ret = write_stream_list(&stream_list, + w->lookup_table, + w->out_fd, + wimlib_get_compression_type(w), + write_flags, + num_threads, + progress_func); + if (ret) + goto out_truncate; + + for (int i = 0; i < w->hdr.image_count; i++) { + if (w->image_metadata[i]->modified) { + select_wim_image(w, i + 1); + ret = write_metadata_resource(w); + if (ret) + goto out_truncate; } - w->out_fp = NULL; } + write_flags |= WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE; + ret = finish_write(w, WIMLIB_ALL_IMAGES, write_flags, + progress_func); +out_truncate: + close_wim_writable(w); + if (ret != 0 && !(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) { + WARNING("Truncating `%"TS"' to its original size (%"PRIu64" bytes)", + w->filename, old_wim_end); + /* Return value of truncate() is ignored because this is already + * an error path. */ + (void)ttruncate(w->filename, old_wim_end); + } + w->wim_locked = 0; + return ret; +} + +static int +overwrite_wim_via_tmpfile(WIMStruct *w, int write_flags, + unsigned num_threads, + wimlib_progress_func_t progress_func) +{ + size_t wim_name_len; + int ret; + + DEBUG("Overwriting `%"TS"' via a temporary file", w->filename); + + /* Write the WIM to a temporary file in the same directory as the + * original WIM. */ + wim_name_len = tstrlen(w->filename); + tchar tmpfile[wim_name_len + 10]; + tmemcpy(tmpfile, w->filename, wim_name_len); + randomize_char_array_with_alnum(tmpfile + wim_name_len, 9); + tmpfile[wim_name_len + 9] = T('\0'); + + ret = wimlib_write(w, tmpfile, WIMLIB_ALL_IMAGES, + write_flags | WIMLIB_WRITE_FLAG_FSYNC, + num_threads, progress_func); + if (ret) { + ERROR("Failed to write the WIM file `%"TS"'", tmpfile); + goto out_unlink; + } + + close_wim(w); + + DEBUG("Renaming `%"TS"' to `%"TS"'", tmpfile, w->filename); + /* Rename the new file to the old file .*/ + if (trename(tmpfile, w->filename) != 0) { + ERROR_WITH_ERRNO("Failed to rename `%"TS"' to `%"TS"'", + tmpfile, w->filename); + ret = WIMLIB_ERR_RENAME; + goto out_unlink; + } + + if (progress_func) { + union wimlib_progress_info progress; + progress.rename.from = tmpfile; + progress.rename.to = w->filename; + progress_func(WIMLIB_PROGRESS_MSG_RENAME, &progress); + } + goto out; +out_unlink: + /* Remove temporary file. */ + if (tunlink(tmpfile) != 0) + WARNING_WITH_ERRNO("Failed to remove `%"TS"'", tmpfile); +out: return ret; } + +/* + * Writes a WIM file to the original file that it was read from, overwriting it. + */ +WIMLIBAPI int +wimlib_overwrite(WIMStruct *w, int write_flags, + unsigned num_threads, + wimlib_progress_func_t progress_func) +{ + int ret; + + write_flags &= WIMLIB_WRITE_MASK_PUBLIC; + + if (!w->filename) + return WIMLIB_ERR_NO_FILENAME; + + ret = can_modify_wim(w); + if (ret) + return ret; + + if ((!w->deletion_occurred || (write_flags & WIMLIB_WRITE_FLAG_SOFT_DELETE)) + && !(write_flags & WIMLIB_WRITE_FLAG_REBUILD)) + { + int ret; + ret = overwrite_wim_inplace(w, write_flags, num_threads, + progress_func); + if (ret == WIMLIB_ERR_RESOURCE_ORDER) + WARNING("Falling back to re-building entire WIM"); + else + return ret; + } + return overwrite_wim_via_tmpfile(w, write_flags, num_threads, + progress_func); +}