X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fwrite.c;h=c346e61c65c57e51b629e5d306799724255d18f4;hp=3866bed6934c80c78a902a7dffddbaa649b2170b;hb=ebd6c0ec0ff47ac18af4ef918fd78fb8d9f19540;hpb=6f7956a06fcf92a304fae93e393e8eaee34e92d5 diff --git a/src/write.c b/src/write.c index 3866bed6..c346e61c 100644 --- a/src/write.c +++ b/src/write.c @@ -6,356 +6,1566 @@ */ /* - * 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. * * wimlib is free software; you can redistribute it and/or modify it under the - * terms of the GNU Lesser General Public License as published by the Free - * Software Foundation; either version 2.1 of the License, or (at your option) + * terms of the GNU General Public License as published by the Free + * Software Foundation; either version 3 of the License, or (at your option) * any later version. * * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR - * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more + * A PARTICULAR PURPOSE. See the GNU General Public License for more * details. * - * You should have received a copy of the GNU Lesser General Public License + * You should have received a copy of the GNU General Public License * along with wimlib; if not, see http://www.gnu.org/licenses/. */ +#include "config.h" + +#if defined(HAVE_SYS_FILE_H) && defined(HAVE_FLOCK) +/* On BSD, this should be included before "list.h" so that "list.h" can + * overwrite the LIST_HEAD macro. */ +#include +#endif + +#include "list.h" #include "wimlib_internal.h" -#include "io.h" +#include "buffer_io.h" #include "dentry.h" #include "lookup_table.h" #include "xml.h" +#include "lzx.h" +#include "xpress.h" + +#ifdef ENABLE_MULTITHREADED_COMPRESSION +#include +#endif + #include +#include + +#ifdef WITH_NTFS_3G +#include +#include +#include +#include +#endif -/* Reopens the FILE* for a WIM read-write. */ -static int reopen_rw(WIMStruct *w) +#ifdef HAVE_ALLOCA_H +#include +#else +#include +#endif + +static int fflush_and_ftruncate(FILE *fp, off_t size) { - FILE *fp; + int ret; - 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; + ret = fflush(fp); + if (ret != 0) { + ERROR_WITH_ERRNO("Failed to flush data to output WIM file"); + return WIMLIB_ERR_WRITE; + } + ret = ftruncate(fileno(fp), size); + if (ret != 0) { + ERROR_WITH_ERRNO("Failed to truncate output WIM file to " + "%"PRIu64" bytes", size); + return WIMLIB_ERR_WRITE; } - w->fp = fp; return 0; } +/* 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 num_chunks; + u64 original_resource_size; + u64 bytes_per_chunk_entry; + u64 table_disk_size; + u64 cur_offset; + u64 *cur_offset_p; + u64 offsets[0]; +}; +/* + * 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, + FILE *out_fp, + off_t file_offset, + struct chunk_table **chunk_tab_ret) +{ + u64 size = wim_resource_size(lte); + u64 num_chunks = (size + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE; + size_t alloc_size = sizeof(struct chunk_table) + num_chunks * sizeof(u64); + struct chunk_table *chunk_tab = CALLOC(1, alloc_size); + int ret; -/* - * Writes a WIM file to the original file that it was read from, overwriting it. + if (!chunk_tab) { + ERROR("Failed to allocate chunk table for %"PRIu64" byte " + "resource", size); + ret = WIMLIB_ERR_NOMEM; + goto out; + } + chunk_tab->file_offset = file_offset; + chunk_tab->num_chunks = num_chunks; + chunk_tab->original_resource_size = size; + chunk_tab->bytes_per_chunk_entry = (size >= (1ULL << 32)) ? 8 : 4; + chunk_tab->table_disk_size = chunk_tab->bytes_per_chunk_entry * + (num_chunks - 1); + chunk_tab->cur_offset = 0; + chunk_tab->cur_offset_p = chunk_tab->offsets; + + if (fwrite(chunk_tab, 1, chunk_tab->table_disk_size, out_fp) != + chunk_tab->table_disk_size) { + ERROR_WITH_ERRNO("Failed to write chunk table in compressed " + "file resource"); + ret = WIMLIB_ERR_WRITE; + goto out; + } + + ret = 0; +out: + *chunk_tab_ret = chunk_tab; + return ret; +} + +/* + * Pointer to function to compresses a chunk of a WIM resource. + * + * @chunk: Uncompressed data of the chunk. + * @chunk_size: Size of the uncompressed chunk in bytes. + * @compressed_chunk: Pointer to output buffer of size at least + * (@chunk_size - 1) bytes. + * @compressed_chunk_len_ret: Pointer to an unsigned int into which the size + * of the compressed chunk will be + * returned. + * + * Returns zero if compressed succeeded, and nonzero if the chunk could not be + * compressed to any smaller than @chunk_size. This function cannot fail for + * any other reasons. */ -WIMLIBAPI int wimlib_overwrite(WIMStruct *w, int flags) +typedef int (*compress_func_t)(const void *, unsigned, void *, unsigned *); + +compress_func_t get_compress_func(int out_ctype) +{ + if (out_ctype == WIMLIB_COMPRESSION_TYPE_LZX) + return lzx_compress; + else + return 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_fp: FILE * to write tho chunk to. + * @out_ctype: Compression type to use when writing the chunk (ignored if no + * chunk table provided) + * @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 u8 chunk[], unsigned chunk_size, + FILE *out_fp, compress_func_t compress, + struct chunk_table *chunk_tab) +{ + const u8 *out_chunk; + unsigned out_chunk_size; + if (chunk_tab) { + u8 *compressed_chunk = alloca(chunk_size); + int ret; + + ret = compress(chunk, chunk_size, compressed_chunk, + &out_chunk_size); + if (ret == 0) { + out_chunk = compressed_chunk; + } else { + out_chunk = chunk; + out_chunk_size = chunk_size; + } + *chunk_tab->cur_offset_p++ = chunk_tab->cur_offset; + chunk_tab->cur_offset += out_chunk_size; + } else { + out_chunk = chunk; + out_chunk_size = chunk_size; + } + if (fwrite(out_chunk, 1, out_chunk_size, out_fp) != out_chunk_size) { + ERROR_WITH_ERRNO("Failed to write WIM resource chunk"); + return WIMLIB_ERR_WRITE; + } + 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, + FILE *out_fp, u64 *compressed_size_p) +{ + size_t bytes_written; + if (fseeko(out_fp, chunk_tab->file_offset, SEEK_SET) != 0) { + ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of output " + "WIM file", chunk_tab->file_offset); + return WIMLIB_ERR_WRITE; + } + + if (chunk_tab->bytes_per_chunk_entry == 8) { + array_cpu_to_le64(chunk_tab->offsets, chunk_tab->num_chunks); + } else { + for (u64 i = 0; i < chunk_tab->num_chunks; i++) + ((u32*)chunk_tab->offsets)[i] = + cpu_to_le32(chunk_tab->offsets[i]); + } + bytes_written = fwrite((u8*)chunk_tab->offsets + + chunk_tab->bytes_per_chunk_entry, + 1, chunk_tab->table_disk_size, out_fp); + 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 (fseeko(out_fp, 0, SEEK_END) != 0) { + ERROR_WITH_ERRNO("Failed to seek to end of output WIM file"); + return WIMLIB_ERR_WRITE; + } + *compressed_size_p = chunk_tab->cur_offset + chunk_tab->table_disk_size; + return 0; +} + +/* Prepare for multiple reads to a resource by caching a FILE * or NTFS + * attribute pointer in the lookup table entry. */ +static int prepare_resource_for_read(struct wim_lookup_table_entry *lte + + #ifdef WITH_NTFS_3G + , ntfs_inode **ni_ret + #endif + ) +{ + switch (lte->resource_location) { + case RESOURCE_IN_FILE_ON_DISK: + if (!lte->file_on_disk_fp) { + lte->file_on_disk_fp = fopen(lte->file_on_disk, "rb"); + if (!lte->file_on_disk_fp) { + ERROR_WITH_ERRNO("Failed to open the file " + "`%s'", lte->file_on_disk); + return WIMLIB_ERR_OPEN; + } + } + break; +#ifdef WITH_NTFS_3G + case RESOURCE_IN_NTFS_VOLUME: + if (!lte->attr) { + struct ntfs_location *loc = lte->ntfs_loc; + ntfs_inode *ni; + wimlib_assert(loc); + ni = ntfs_pathname_to_inode(*loc->ntfs_vol_p, NULL, loc->path_utf8); + if (!ni) { + ERROR_WITH_ERRNO("Failed to open inode `%s' in NTFS " + "volume", loc->path_utf8); + return WIMLIB_ERR_NTFS_3G; + } + lte->attr = ntfs_attr_open(ni, + loc->is_reparse_point ? AT_REPARSE_POINT : AT_DATA, + (ntfschar*)loc->stream_name_utf16, + loc->stream_name_utf16_num_chars); + if (!lte->attr) { + ERROR_WITH_ERRNO("Failed to open attribute of `%s' in " + "NTFS volume", loc->path_utf8); + ntfs_inode_close(ni); + return WIMLIB_ERR_NTFS_3G; + } + *ni_ret = ni; + } + break; +#endif +#if defined(__CYGWIN__) || defined(__WIN32__) + case RESOURCE_WIN32: + if (!lte->file_on_disk_fp) { + lte->file_on_disk_fp = win32_open_handle(lte->file_on_disk); + if (!lte->file_on_disk_fp) + return WIMLIB_ERR_OPEN; + } + break; +#endif + default: + break; + } + return 0; +} + +/* Undo prepare_resource_for_read() by closing the cached FILE * or NTFS + * attribute. */ +static void end_wim_resource_read(struct wim_lookup_table_entry *lte + #ifdef WITH_NTFS_3G + , ntfs_inode *ni + #endif + ) +{ + if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK + && lte->file_on_disk_fp) + { + fclose(lte->file_on_disk_fp); + lte->file_on_disk_fp = NULL; + } +#ifdef WITH_NTFS_3G + else if (lte->resource_location == RESOURCE_IN_NTFS_VOLUME) { + if (lte->attr) { + ntfs_attr_close(lte->attr); + lte->attr = NULL; + } + if (ni) + ntfs_inode_close(ni); + } +#endif +#if defined(__CYGWIN__) || defined(__WIN32__) + else if (lte->resource_location == RESOURCE_WIN32 + && lte->file_on_disk_fp) + { + win32_close_handle(lte->file_on_disk_fp); + lte->file_on_disk_fp = NULL; + } +#endif +} + +static int +write_uncompressed_resource_and_truncate(struct wim_lookup_table_entry *lte, + FILE *out_fp, + off_t file_offset, + struct resource_entry *out_res_entry) { - const char *wimfile_name; - size_t wim_name_len; int ret; - - wimfile_name = w->filename; + if (fseeko(out_fp, file_offset, SEEK_SET) != 0) { + ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of " + "output WIM file", file_offset); + return WIMLIB_ERR_WRITE; + } + ret = write_wim_resource(lte, out_fp, WIMLIB_COMPRESSION_TYPE_NONE, + out_res_entry, 0); + if (ret != 0) + return ret; - DEBUG("Replacing WIM file `%s'.", wimfile_name); + return fflush_and_ftruncate(out_fp, + file_offset + wim_resource_size(lte)); +} - if (!wimfile_name) - return WIMLIB_ERR_NO_FILENAME; +/* + * Writes a WIM resource to a FILE * opened for writing. The resource may be + * written uncompressed or compressed depending on the @out_ctype parameter. + * + * If by chance the resource compresses to more than the original size (this may + * happen with random data or files than are pre-compressed), the resource is + * instead written uncompressed (and this is reflected in the @out_res_entry by + * removing the WIM_RESHDR_FLAG_COMPRESSED flag). + * + * @lte: The lookup table entry for the WIM resource. + * @out_fp: The FILE * to write the resource to. + * @out_ctype: The compression type of the resource to write. Note: if this is + * the same as the compression type of the WIM resource we + * need to read, we simply copy the data (i.e. we do not + * uncompress it, then compress it again). + * @out_res_entry: If non-NULL, a resource entry that is filled in with the + * offset, original size, compressed size, and compression flag + * of the output resource. + * + * Returns 0 on success; nonzero on failure. + */ +int write_wim_resource(struct wim_lookup_table_entry *lte, + FILE *out_fp, int out_ctype, + struct resource_entry *out_res_entry, + int flags) +{ + u64 bytes_remaining; + u64 original_size; + u64 old_compressed_size; + u64 new_compressed_size; + u64 offset; + int ret; + struct chunk_table *chunk_tab = NULL; + bool raw; + off_t file_offset; + compress_func_t compress = NULL; +#ifdef WITH_NTFS_3G + ntfs_inode *ni = NULL; +#endif + + wimlib_assert(lte); + + /* Original size of the resource */ + original_size = wim_resource_size(lte); + + /* Compressed size of the resource (as it exists now) */ + old_compressed_size = wim_resource_compressed_size(lte); + + /* Current offset in output file */ + file_offset = ftello(out_fp); + if (file_offset == -1) { + ERROR_WITH_ERRNO("Failed to get offset in output " + "stream"); + return WIMLIB_ERR_WRITE; + } + + /* Are the compression types the same? If so, do a raw copy (copy + * without decompressing and recompressing the data). */ + raw = (wim_resource_compression_type(lte) == out_ctype + && out_ctype != WIMLIB_COMPRESSION_TYPE_NONE + && !(flags & WIMLIB_RESOURCE_FLAG_RECOMPRESS)); + + if (raw) { + flags |= WIMLIB_RESOURCE_FLAG_RAW; + bytes_remaining = old_compressed_size; + } else { + flags &= ~WIMLIB_RESOURCE_FLAG_RAW; + bytes_remaining = original_size; + } + + /* Empty resource; nothing needs to be done, so just return success. */ + if (bytes_remaining == 0) + return 0; + + /* Buffer for reading chunks for the resource */ + u8 buf[min(WIM_CHUNK_SIZE, bytes_remaining)]; + + /* If we are writing a compressed resource and not doing a raw copy, we + * need to initialize the chunk table */ + if (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE && !raw) { + ret = begin_wim_resource_chunk_tab(lte, out_fp, file_offset, + &chunk_tab); + if (ret != 0) + goto out; + } + + /* If the WIM resource is in an external file, open a FILE * to it so we + * don't have to open a temporary one in read_wim_resource() for each + * chunk. */ +#ifdef WITH_NTFS_3G + ret = prepare_resource_for_read(lte, &ni); +#else + ret = prepare_resource_for_read(lte); +#endif + if (ret != 0) + goto out; + + /* If we aren't doing a raw copy, we will compute the SHA1 message + * digest of the resource as we read it, and verify it's the same as the + * hash given in the lookup table entry once we've finished reading the + * resource. */ + SHA_CTX ctx; + if (!raw) { + sha1_init(&ctx); + compress = get_compress_func(out_ctype); + } + offset = 0; + + /* While there are still bytes remaining in the WIM resource, read a + * chunk of the resource, update SHA1, then write that chunk using the + * desired compression type. */ + do { + u64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE); + ret = read_wim_resource(lte, buf, to_read, offset, flags); + if (ret != 0) + goto out_fclose; + if (!raw) + sha1_update(&ctx, buf, to_read); + ret = write_wim_resource_chunk(buf, to_read, out_fp, + compress, chunk_tab); + if (ret != 0) + goto out_fclose; + bytes_remaining -= to_read; + offset += to_read; + } while (bytes_remaining); + + /* Raw copy: The new compressed size is the same as the old compressed + * size + * + * Using WIMLIB_COMPRESSION_TYPE_NONE: The new compressed size is the + * original size + * + * Using a different compression type: Call + * finish_wim_resource_chunk_tab() and it will provide the new + * compressed size. + */ + if (raw) { + new_compressed_size = old_compressed_size; + } else { + if (out_ctype == WIMLIB_COMPRESSION_TYPE_NONE) + new_compressed_size = original_size; + else { + ret = finish_wim_resource_chunk_tab(chunk_tab, out_fp, + &new_compressed_size); + if (ret != 0) + goto out_fclose; + } + } + + /* Verify SHA1 message digest of the resource, unless we are doing a raw + * write (in which case we never even saw the uncompressed data). Or, + * if the hash we had before is all 0's, just re-set it to be the new + * hash. */ + if (!raw) { + u8 md[SHA1_HASH_SIZE]; + sha1_final(md, &ctx); + if (is_zero_hash(lte->hash)) { + copy_hash(lte->hash, md); + } else if (!hashes_equal(md, lte->hash)) { + ERROR("WIM resource has incorrect hash!"); + if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK) { + ERROR("We were reading it from `%s'; maybe it changed " + "while we were reading it.", + lte->file_on_disk); + } + ret = WIMLIB_ERR_INVALID_RESOURCE_HASH; + goto out_fclose; + } + } + + if (!raw && new_compressed_size >= original_size && + out_ctype != WIMLIB_COMPRESSION_TYPE_NONE) + { + /* Oops! We compressed the resource to larger than the original + * size. Write the resource uncompressed instead. */ + ret = write_uncompressed_resource_and_truncate(lte, + out_fp, + file_offset, + out_res_entry); + if (ret != 0) + goto out_fclose; + } else { + if (out_res_entry) { + out_res_entry->size = new_compressed_size; + out_res_entry->original_size = original_size; + out_res_entry->offset = file_offset; + out_res_entry->flags = lte->resource_entry.flags + & ~WIM_RESHDR_FLAG_COMPRESSED; + if (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE) + out_res_entry->flags |= WIM_RESHDR_FLAG_COMPRESSED; + } + } + ret = 0; +out_fclose: +#ifdef WITH_NTFS_3G + end_wim_resource_read(lte, ni); +#else + end_wim_resource_read(lte); +#endif +out: + FREE(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) + return WIMLIB_ERR_NOMEM; + q->filled_slots = 0; + q->front = 0; + q->back = size - 1; + q->size = size; + pthread_mutex_init(&q->lock, NULL); + pthread_cond_init(&q->msg_avail_cond, NULL); + pthread_cond_init(&q->space_avail_cond, NULL); + return 0; +} + +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); +} + +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 *out_compressed_chunks[MAX_CHUNKS_PER_MSG]; + u8 *compressed_chunks[MAX_CHUNKS_PER_MSG]; + unsigned uncompressed_chunk_sizes[MAX_CHUNKS_PER_MSG]; + unsigned compressed_chunk_sizes[MAX_CHUNKS_PER_MSG]; + unsigned num_chunks; + struct list_head list; + bool complete; + u64 begin_chunk; +}; + +static void compress_chunks(struct message *msg, compress_func_t compress) +{ + for (unsigned i = 0; i < msg->num_chunks; i++) { + DEBUG2("compress chunk %u of %u", i, msg->num_chunks); + int ret = compress(msg->uncompressed_chunks[i], + msg->uncompressed_chunk_sizes[i], + msg->compressed_chunks[i], + &msg->compressed_chunk_sizes[i]); + if (ret == 0) { + msg->out_compressed_chunks[i] = msg->compressed_chunks[i]; + } else { + msg->out_compressed_chunks[i] = msg->uncompressed_chunks[i]; + msg->compressed_chunk_sizes[i] = msg->uncompressed_chunk_sizes[i]; + } + } +} + +/* 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 + +static int do_write_stream_list(struct list_head *my_resources, + FILE *out_fp, + int out_ctype, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress, + int write_resource_flags) +{ + int ret; + struct wim_lookup_table_entry *lte, *tmp; + + list_for_each_entry_safe(lte, tmp, my_resources, staging_list) { + ret = write_wim_resource(lte, + out_fp, + out_ctype, + <e->output_resource_entry, + write_resource_flags); + if (ret != 0) + return ret; + list_del(<e->staging_list); + progress->write_streams.completed_bytes += + wim_resource_size(lte); + progress->write_streams.completed_streams++; + if (progress_func) { + progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, + progress); + } + } + return 0; +} + +static int write_stream_list_serial(struct list_head *stream_list, + FILE *out_fp, + int out_ctype, + int write_flags, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress) +{ + int write_resource_flags; + + if (write_flags & WIMLIB_WRITE_FLAG_RECOMPRESS) + write_resource_flags = WIMLIB_RESOURCE_FLAG_RECOMPRESS; + else + write_resource_flags = 0; + progress->write_streams.num_threads = 1; + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); + return do_write_stream_list(stream_list, out_fp, + out_ctype, progress_func, + progress, write_resource_flags); +} + +#ifdef ENABLE_MULTITHREADED_COMPRESSION +static int write_wim_chunks(struct message *msg, FILE *out_fp, + struct chunk_table *chunk_tab) +{ + for (unsigned i = 0; i < msg->num_chunks; i++) { + unsigned chunk_csize = msg->compressed_chunk_sizes[i]; + + DEBUG2("Write wim chunk %u of %u (csize = %u)", + i, msg->num_chunks, chunk_csize); + + if (fwrite(msg->out_compressed_chunks[i], 1, chunk_csize, out_fp) + != chunk_csize) + { + ERROR_WITH_ERRNO("Failed to write WIM chunk"); + return WIMLIB_ERR_WRITE; + } + + *chunk_tab->cur_offset_p++ = chunk_tab->cur_offset; + chunk_tab->cur_offset += chunk_csize; + } + return 0; +} + +/* + * This function is executed by the main thread when the resources are being + * compressed in parallel. The main thread is in change of all reading of the + * uncompressed data and writing of the compressed data. The compressor threads + * *only* do compression from/to in-memory buffers. + * + * Each unit of work given to a compressor thread is up to MAX_CHUNKS_PER_MSG + * chunks of compressed data to compress, represented in a `struct message'. + * Each message is passed from the main thread to a worker thread through the + * res_to_compress_queue, and it is passed back through the + * compressed_res_queue. + */ +static int main_writer_thread_proc(struct list_head *stream_list, + FILE *out_fp, + int out_ctype, + struct shared_queue *res_to_compress_queue, + struct shared_queue *compressed_res_queue, + size_t num_messages, + int write_flags, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress) +{ + int ret; + struct chunk_table *cur_chunk_tab = NULL; + struct message *msgs = CALLOC(num_messages, sizeof(struct message)); + struct wim_lookup_table_entry *next_lte = NULL; + + // Initially, all the messages are available to use. + LIST_HEAD(available_msgs); + + if (!msgs) { + ret = WIMLIB_ERR_NOMEM; + goto out; + } + + for (size_t i = 0; i < num_messages; i++) + list_add(&msgs[i].list, &available_msgs); + + // outstanding_resources is the list of resources that currently have + // had chunks sent off for compression. + // + // The first stream in outstanding_resources is the stream that is + // currently being written (cur_lte). + // + // The last stream in outstanding_resources is the stream that is + // currently being read and chunks fed to the compressor threads + // (next_lte). + // + // Depending on the number of threads and the sizes of the resource, + // the outstanding streams list may contain streams between cur_lte and + // next_lte that have all their chunks compressed or being compressed, + // but haven't been written yet. + // + LIST_HEAD(outstanding_resources); + struct list_head *next_resource = stream_list->next; + u64 next_chunk = 0; + u64 next_num_chunks = 0; + + // As in write_wim_resource(), each resource we read is checksummed. + SHA_CTX next_sha_ctx; + u8 next_hash[SHA1_HASH_SIZE]; + + // Resources that don't need any chunks compressed are added to this + // list and written directly by the main thread. + LIST_HEAD(my_resources); + + struct wim_lookup_table_entry *cur_lte = NULL; + struct message *msg; + +#ifdef WITH_NTFS_3G + ntfs_inode *ni = NULL; +#endif + + DEBUG("Initializing buffers for uncompressed " + "and compressed data (%zu bytes needed)", + num_messages * MAX_CHUNKS_PER_MSG * WIM_CHUNK_SIZE * 2); + + // Pre-allocate all the buffers that will be needed to do the chunk + // compression. + for (size_t i = 0; i < num_messages; i++) { + for (size_t j = 0; j < MAX_CHUNKS_PER_MSG; j++) { + msgs[i].compressed_chunks[j] = MALLOC(WIM_CHUNK_SIZE); + + // The extra 8 bytes is because longest_match() in + // lz77.c may read a little bit off the end of the + // uncompressed data. It doesn't need to be + // initialized--- we really just need to avoid accessing + // an unmapped page. + msgs[i].uncompressed_chunks[j] = MALLOC(WIM_CHUNK_SIZE + 8); + if (msgs[i].compressed_chunks[j] == NULL || + msgs[i].uncompressed_chunks[j] == NULL) + { + ret = WIMLIB_ERR_NOMEM; + goto out; + } + } + } + + // This loop is executed until all resources have been written, except + // possibly a few that have been added to the @my_resources list for + // writing later. + while (1) { + // Send chunks to the compressor threads until either (a) there + // are no more messages available since they were all sent off, + // or (b) there are no more resources that need to be + // compressed. + while (!list_empty(&available_msgs)) { + if (next_chunk == next_num_chunks) { + // If next_chunk == next_num_chunks, there are + // no more chunks to write in the current + // stream. So, check the SHA1 message digest of + // the stream that was just finished (unless + // next_lte == NULL, which is the case the very + // first time this loop is entered, and also + // near the very end of the compression when + // there are no more streams.) Then, advance to + // the next stream (if there is one). + if (next_lte != NULL) { + #ifdef WITH_NTFS_3G + end_wim_resource_read(next_lte, ni); + ni = NULL; + #else + end_wim_resource_read(next_lte); + #endif + DEBUG2("Finalize SHA1 md (next_num_chunks=%zu)", + next_num_chunks); + sha1_final(next_hash, &next_sha_ctx); + if (!hashes_equal(next_lte->hash, next_hash)) { + ERROR("WIM resource has incorrect hash!"); + if (next_lte->resource_location == + RESOURCE_IN_FILE_ON_DISK) + { + ERROR("We were reading it from `%s'; " + "maybe it changed while we were " + "reading it.", + next_lte->file_on_disk); + } + ret = WIMLIB_ERR_INVALID_RESOURCE_HASH; + goto out; + } + } + + // Advance to the next resource. + // + // If the next resource needs no compression, just write + // it with this thread (not now though--- we could be in + // the middle of writing another resource.) Keep doing + // this until we either get to the end of the resources + // list, or we get to a resource that needs compression. + while (1) { + if (next_resource == stream_list) { + // No more resources to send for + // compression + next_lte = NULL; + break; + } + next_lte = container_of(next_resource, + struct wim_lookup_table_entry, + staging_list); + next_resource = next_resource->next; + if ((!(write_flags & WIMLIB_WRITE_FLAG_RECOMPRESS) + && wim_resource_compression_type(next_lte) == out_ctype) + || wim_resource_size(next_lte) == 0) + { + list_add_tail(&next_lte->staging_list, + &my_resources); + } else { + list_add_tail(&next_lte->staging_list, + &outstanding_resources); + next_chunk = 0; + next_num_chunks = wim_resource_chunks(next_lte); + sha1_init(&next_sha_ctx); + INIT_LIST_HEAD(&next_lte->msg_list); + #ifdef WITH_NTFS_3G + ret = prepare_resource_for_read(next_lte, &ni); + #else + ret = prepare_resource_for_read(next_lte); + #endif + + if (ret != 0) + goto out; + if (cur_lte == NULL) { + // Set cur_lte for the + // first time + cur_lte = next_lte; + } + break; + } + } + } + + if (next_lte == NULL) { + // No more resources to send for compression + break; + } + + // Get a message from the available messages + // list + msg = container_of(available_msgs.next, + struct message, + list); + + // ... and delete it from the available messages + // list + list_del(&msg->list); + + // Initialize the message with the chunks to + // compress. + msg->num_chunks = min(next_num_chunks - next_chunk, + MAX_CHUNKS_PER_MSG); + msg->lte = next_lte; + msg->complete = false; + msg->begin_chunk = next_chunk; + + unsigned size = WIM_CHUNK_SIZE; + for (unsigned i = 0; i < msg->num_chunks; i++) { + + // Read chunk @next_chunk of the stream into the + // message so that a compressor thread can + // compress it. + + if (next_chunk == next_num_chunks - 1) { + size = MODULO_NONZERO(wim_resource_size(next_lte), + WIM_CHUNK_SIZE); + } + + DEBUG2("Read resource (size=%u, offset=%zu)", + size, next_chunk * WIM_CHUNK_SIZE); + + msg->uncompressed_chunk_sizes[i] = size; + + ret = read_wim_resource(next_lte, + msg->uncompressed_chunks[i], + size, + next_chunk * WIM_CHUNK_SIZE, + 0); + if (ret != 0) + goto out; + sha1_update(&next_sha_ctx, + msg->uncompressed_chunks[i], size); + next_chunk++; + } + + // Send the compression request + list_add_tail(&msg->list, &next_lte->msg_list); + shared_queue_put(res_to_compress_queue, msg); + DEBUG2("Compression request sent"); + } + + // If there are no outstanding resources, there are no more + // resources that need to be written. + if (list_empty(&outstanding_resources)) { + ret = 0; + goto out; + } + + // 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(compressed_res_queue); + msg->complete = true; + + // 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) + { + DEBUG2("Complete msg (begin_chunk=%"PRIu64")", msg->begin_chunk); + if (msg->begin_chunk == 0) { + DEBUG2("Begin chunk tab"); + + // This is the first set of chunks. Leave space + // for the chunk table in the output file. + off_t cur_offset = ftello(out_fp); + if (cur_offset == -1) { + ret = WIMLIB_ERR_WRITE; + goto out; + } + ret = begin_wim_resource_chunk_tab(cur_lte, + out_fp, + cur_offset, + &cur_chunk_tab); + if (ret != 0) + goto out; + } + + // Write the compressed chunks from the message. + ret = write_wim_chunks(msg, out_fp, cur_chunk_tab); + if (ret != 0) + goto out; + + list_del(&msg->list); + + // This message is available to use for different chunks + // now. + list_add(&msg->list, &available_msgs); + + // 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 == cur_chunk_tab->num_chunks) + { + DEBUG2("Finish wim chunk tab"); + u64 res_csize; + ret = finish_wim_resource_chunk_tab(cur_chunk_tab, + out_fp, + &res_csize); + if (ret != 0) + goto out; + + if (res_csize >= wim_resource_size(cur_lte)) { + /* Oops! We compressed the resource to + * larger than the original size. Write + * the resource uncompressed instead. */ + ret = write_uncompressed_resource_and_truncate( + cur_lte, + out_fp, + cur_chunk_tab->file_offset, + &cur_lte->output_resource_entry); + if (ret != 0) + goto out; + } 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 = + cur_chunk_tab->file_offset; + + cur_lte->output_resource_entry.flags = + cur_lte->resource_entry.flags | + WIM_RESHDR_FLAG_COMPRESSED; + } + + progress->write_streams.completed_bytes += + wim_resource_size(cur_lte); + progress->write_streams.completed_streams++; + + if (progress_func) { + progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, + progress); + } + + FREE(cur_chunk_tab); + cur_chunk_tab = NULL; + + struct list_head *next = cur_lte->staging_list.next; + list_del(&cur_lte->staging_list); + + if (next == &outstanding_resources) + cur_lte = NULL; + else + cur_lte = container_of(cur_lte->staging_list.next, + struct wim_lookup_table_entry, + staging_list); + + // Since we just finished writing a stream, + // write any streams that have been added to the + // my_resources 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). + ret = do_write_stream_list(&my_resources, + out_fp, + out_ctype, + progress_func, + progress, + 0); + if (ret != 0) + goto out; + } + } + } + +out: + if (ret == WIMLIB_ERR_NOMEM) { + ERROR("Could not allocate enough memory for " + "multi-threaded compression"); + } + + if (next_lte) { +#ifdef WITH_NTFS_3G + end_wim_resource_read(next_lte, ni); +#else + end_wim_resource_read(next_lte); +#endif + } + + if (ret == 0) { + ret = do_write_stream_list(&my_resources, out_fp, + out_ctype, progress_func, + progress, 0); + } else { + if (msgs) { + size_t num_available_msgs = 0; + struct list_head *cur; + + list_for_each(cur, &available_msgs) { + num_available_msgs++; + } + + while (num_available_msgs < num_messages) { + shared_queue_get(compressed_res_queue); + num_available_msgs++; + } + } + } + + if (msgs) { + for (size_t i = 0; i < num_messages; i++) { + for (size_t j = 0; j < MAX_CHUNKS_PER_MSG; j++) { + FREE(msgs[i].compressed_chunks[j]); + FREE(msgs[i].uncompressed_chunks[j]); + } + } + FREE(msgs); + } + + FREE(cur_chunk_tab); + return ret; +} + + +static int write_stream_list_parallel(struct list_head *stream_list, + FILE *out_fp, + int out_ctype, + int write_flags, + unsigned num_threads, + wimlib_progress_func_t progress_func, + union wimlib_progress_info *progress) +{ + 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 = sysconf(_SC_NPROCESSORS_ONLN); + if (nthreads < 1) { + WARNING("Could not determine number of processors! Assuming 1"); + goto out_serial; + } else { + num_threads = nthreads; + } + } + + progress->write_streams.num_threads = num_threads; + wimlib_assert(stream_list->next != stream_list); + + static const double MESSAGES_PER_THREAD = 2.0; + 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 != 0) + goto out_serial; + + ret = shared_queue_init(&compressed_res_queue, queue_size); + if (ret != 0) + goto out_destroy_res_to_compress_queue; - /* 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'; + 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); - ret = wimlib_write(w, tmpfile, WIM_ALL_IMAGES, flags); - if (ret != 0) { - ERROR("Failed to write the WIM file `%s'", tmpfile); - return ret; + compressor_threads = MALLOC(num_threads * sizeof(pthread_t)); + if (!compressor_threads) { + ret = WIMLIB_ERR_NOMEM; + goto out_destroy_compressed_res_queue; } - 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); + for (unsigned i = 0; i < num_threads; i++) { + DEBUG("pthread_create thread %u", i); + 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", i); + num_threads = i; + goto out_join; } - w->fp = NULL; } - DEBUG("Renaming `%s' to `%s'", tmpfile, wimfile_name); + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress); - /* 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; + ret = main_writer_thread_proc(stream_list, + out_fp, + out_ctype, + &res_to_compress_queue, + &compressed_res_queue, + queue_size, + write_flags, + progress_func, + progress); +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", i); + } } + 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"); + return write_stream_list_serial(stream_list, + out_fp, + out_ctype, + write_flags, + progress_func, + progress); - return 0; } +#endif - -WIMLIBAPI int wimlib_overwrite_xml_and_header(WIMStruct *w, int flags) +/* + * Write a list of streams to a WIM (@out_fp) using the compression type + * @out_ctype and up to @num_threads compressor threads. + */ +static int write_stream_list(struct list_head *stream_list, FILE *out_fp, + int out_ctype, int write_flags, + unsigned num_threads, + wimlib_progress_func_t progress_func) { - int ret; - FILE *fp; - u8 *integrity_table = NULL; - off_t xml_end; - off_t xml_size; - size_t bytes_written; + 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; - DEBUG("Overwriting XML and header of `%s', flags = %d", - w->filename, flags); - if (!w->filename) - return WIMLIB_ERR_NO_FILENAME; + list_for_each_entry(lte, stream_list, staging_list) { + num_streams++; + total_bytes += wim_resource_size(lte); + if (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE + && (wim_resource_compression_type(lte) != out_ctype || + (write_flags & WIMLIB_WRITE_FLAG_RECOMPRESS))) + { + total_compression_bytes += wim_resource_size(lte); + } + } + 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; - ret = reopen_rw(w); - if (ret != 0) - return ret; +#ifdef ENABLE_MULTITHREADED_COMPRESSION + if (total_compression_bytes >= 1000000 && num_threads != 1) + return write_stream_list_parallel(stream_list, + out_fp, + out_ctype, + write_flags, + num_threads, + progress_func, + &progress); + else +#endif + return write_stream_list_serial(stream_list, + out_fp, + out_ctype, + write_flags, + progress_func, + &progress); +} - fp = w->fp; - - /* 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) - return WIMLIB_ERR_NOMEM; - - 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."); - } +struct lte_overwrite_prepare_args { + WIMStruct *wim; + off_t end_offset; + struct list_head *stream_list; +}; - 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; - } - ret = write_xml_data(w->wim_info, WIM_ALL_IMAGES, fp, 0); - if (ret != 0) - goto err; +static int lte_overwrite_prepare(struct wim_lookup_table_entry *lte, void *arg) +{ + struct lte_overwrite_prepare_args *args = arg; - 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; + if (lte->resource_location == RESOURCE_IN_WIM && + lte->wim == args->wim && + 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; } - 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; - } - 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; - } - 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; - } - memset(&w->hdr.integrity, 0, sizeof(struct resource_entry)); + lte->out_refcnt = lte->refcnt; + memcpy(<e->output_resource_entry, <e->resource_entry, + sizeof(struct resource_entry)); + if (!(lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)) { + wimlib_assert(lte->resource_location != RESOURCE_NONEXISTENT); + if (lte->resource_location != RESOURCE_IN_WIM || lte->wim != args->wim) + list_add(<e->staging_list, args->stream_list); } + return 0; +} - 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; - } +static int wim_find_new_streams(WIMStruct *wim, off_t end_offset, + struct list_head *stream_list) +{ + struct lte_overwrite_prepare_args args = { + .wim = wim, + .end_offset = end_offset, + .stream_list = stream_list, + }; - ret = write_header(&w->hdr, fp); - if (ret != 0) - return ret; + return for_lookup_table_entry(wim->lookup_table, + lte_overwrite_prepare, &args); +} - DEBUG("Closing `%s'.", w->filename); - if (fclose(fp) != 0) { - ERROR_WITH_ERRNO("Failed to close `%s'", w->filename); - return WIMLIB_ERR_WRITE; +static int inode_find_streams_to_write(struct wim_inode *inode, + struct wim_lookup_table *table, + struct list_head *stream_list) +{ + 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) + list_add_tail(<e->staging_list, stream_list); + lte->out_refcnt += inode->i_nlink; + } } - w->fp = NULL; - DEBUG("Done."); return 0; -err: - FREE(integrity_table); - return ret; } +static int image_find_streams_to_write(WIMStruct *w) +{ + struct wim_inode *inode; + struct hlist_node *cur; + struct hlist_head *inode_list; + + inode_list = &wim_get_current_image_metadata(w)->inode_list; + hlist_for_each_entry(inode, cur, inode_list, i_hlist) { + inode_find_streams_to_write(inode, w->lookup_table, + (struct list_head*)w->private); + } + return 0; +} -/* Write the file resources for the current image. */ -static int write_file_resources(WIMStruct *w) +static int write_wim_streams(WIMStruct *w, int image, int write_flags, + unsigned num_threads, + wimlib_progress_func_t progress_func) { - DEBUG("Writing file resources for image %u.", w->current_image); - return for_dentry_in_tree(wim_root_dentry(w), write_file_resource, w); + for_lookup_table_entry(w->lookup_table, lte_zero_out_refcnt, NULL); + LIST_HEAD(stream_list); + w->private = &stream_list; + for_image(w, image, image_find_streams_to_write); + return write_stream_list(&stream_list, w->out_fp, + wimlib_get_compression_type(w), write_flags, + num_threads, progress_func); } -/* Write the lookup table, xml data, and integrity table, then overwrite the WIM - * header. +/* + * Finish writing a WIM file: write the lookup table, xml data, and integrity + * table (optional), 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) -{ - off_t lookup_table_offset; - off_t xml_data_offset; - off_t lookup_table_size; - off_t integrity_offset; - off_t xml_data_size; - off_t end_offset; - off_t integrity_size; + * write_flags is a bitwise OR of the following: + * + * (public) WIMLIB_WRITE_FLAG_CHECK_INTEGRITY: + * Include an integrity table. + * + * (public) WIMLIB_WRITE_FLAG_SHOW_PROGRESS: + * Show progress information when (if) writing the 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; FILE *out = w->out_fp; - if (write_lt) { - lookup_table_offset = ftello(out); - if (lookup_table_offset == -1) - return WIMLIB_ERR_WRITE; - - 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; - } - - - xml_data_offset = ftello(out); - if (xml_data_offset == -1) - return WIMLIB_ERR_WRITE; - DEBUG("Writing XML data (offset %"PRIu64")", xml_data_offset); - /* @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; + + if (!(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) { + ret = write_lookup_table(w->lookup_table, out, &hdr.lookup_table_res_entry); + if (ret != 0) + goto out; } - 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)); + ret = write_xml_data(w->wim_info, image, out, + (write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE) ? + wim_info_get_total_bytes(w->wim_info) : 0, + &hdr.xml_res_entry); if (ret != 0) - return ret; + goto out; - integrity_offset = ftello(out); - if (integrity_offset == -1) - return WIMLIB_ERR_WRITE; - xml_data_size = integrity_offset - xml_data_offset; + 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)); + memset(&checkpoint_hdr.integrity, 0, sizeof(struct resource_entry)); + if (fseeko(out, 0, SEEK_SET) != 0) { + ERROR_WITH_ERRNO("Failed to seek to beginning " + "of WIM being written"); + ret = WIMLIB_ERR_WRITE; + goto out; + } + ret = write_header(&checkpoint_hdr, out); + if (ret != 0) + goto out; + + if (fflush(out) != 0) { + ERROR_WITH_ERRNO("Can't write data to WIM"); + ret = WIMLIB_ERR_WRITE; + goto out; + } + + if (fseeko(out, 0, SEEK_END) != 0) { + ERROR_WITH_ERRNO("Failed to seek to end " + "of WIM being written"); + ret = WIMLIB_ERR_WRITE; + goto out; + } + } - 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; + 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; - 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); + ret = write_integrity_table(out, + &hdr.integrity, + new_lookup_table_end, + old_lookup_table_end, + progress_func); 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; + goto out; } else { - hdr.integrity.offset = 0; - hdr.integrity.size = 0; - hdr.integrity.original_size = 0; + memset(&hdr.integrity, 0, sizeof(struct resource_entry)); } - hdr.integrity.flags = 0; - - DEBUG("Updating WIM header."); - /* + /* * 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)); - } else { - memcpy(&hdr.boot_metadata_res_entry, - &w->image_metadata[ - hdr.boot_idx - 1].metadata_lte->output_resource_entry, - sizeof(struct resource_entry)); - } /* Set image count and boot index correctly for single image writes */ - if (image != WIM_ALL_IMAGES) { + if (image != WIMLIB_ALL_IMAGES) { hdr.image_count = 1; if (hdr.boot_idx == image) hdr.boot_idx = 1; @@ -363,82 +1573,425 @@ int finish_write(WIMStruct *w, int image, int flags, int write_lt) hdr.boot_idx = 0; } + if (hdr.boot_idx == 0) { + memset(&hdr.boot_metadata_res_entry, 0, + sizeof(struct resource_entry)); + } else { + memcpy(&hdr.boot_metadata_res_entry, + &w->image_metadata[ + hdr.boot_idx - 1].metadata_lte->output_resource_entry, + sizeof(struct resource_entry)); + } - if (fseeko(out, 0, SEEK_SET) != 0) - return WIMLIB_ERR_WRITE; + if (fseeko(out, 0, SEEK_SET) != 0) { + ERROR_WITH_ERRNO("Failed to seek to beginning of WIM " + "being written"); + ret = WIMLIB_ERR_WRITE; + goto out; + } + + ret = write_header(&hdr, out); + if (ret != 0) + goto out; + + if (write_flags & WIMLIB_WRITE_FLAG_FSYNC) { + if (fflush(out) != 0 + || fsync(fileno(out)) != 0) + { + ERROR_WITH_ERRNO("Error flushing data to WIM file"); + ret = WIMLIB_ERR_WRITE; + } + } +out: + if (fclose(out) != 0) { + ERROR_WITH_ERRNO("Failed to close the WIM file"); + if (ret == 0) + ret = WIMLIB_ERR_WRITE; + } + w->out_fp = NULL; + return ret; +} - return write_header(&hdr, out); +#if defined(HAVE_SYS_FILE_H) && defined(HAVE_FLOCK) +int lock_wim(WIMStruct *w, FILE *fp) +{ + int ret = 0; + if (fp && !w->wim_locked) { + ret = flock(fileno(fp), LOCK_EX | LOCK_NB); + if (ret != 0) { + if (errno == EWOULDBLOCK) { + ERROR("`%s' 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 `%s'", + w->filename); + ret = 0; + } + } else { + w->wim_locked = 1; + } + } + return ret; } +#endif -/* Open file stream and write dummy header for WIM. */ -int begin_write(WIMStruct *w, const char *path, int flags) +static int open_wim_writable(WIMStruct *w, const char *path, + bool trunc, bool readable) { 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"; + if (trunc) + if (readable) + mode = "w+b"; + else + mode = "wb"; else - mode = "wb"; + mode = "r+b"; + wimlib_assert(w->out_fp == NULL); w->out_fp = fopen(path, mode); - if (!w->out_fp) { - ERROR_WITH_ERRNO("Failed to open the file `%s' for writing", - path); + if (w->out_fp) { + return 0; + } else { + ERROR_WITH_ERRNO("Failed to open `%s' for writing", path); return WIMLIB_ERR_OPEN; } +} + + +void close_wim_writable(WIMStruct *w) +{ + if (w->out_fp) { + if (fclose(w->out_fp) != 0) { + WARNING_WITH_ERRNO("Failed to close output WIM"); + } + w->out_fp = NULL; + } +} +/* Open file stream and write dummy header for WIM. */ +int begin_write(WIMStruct *w, const char *path, int write_flags) +{ + int ret; + ret = open_wim_writable(w, path, true, + (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) != 0); + if (ret != 0) + return ret; /* Write dummy header. It will be overwritten later. */ return write_header(&w->hdr, w->out_fp); } -/* 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 char *path, + int image, int write_flags, unsigned num_threads, + wimlib_progress_func_t progress_func) { int ret; - if (image != WIM_ALL_IMAGES && + if (!path) + return WIMLIB_ERR_INVALID_PARAM; + + write_flags &= WIMLIB_WRITE_MASK_PUBLIC; + + if (image != WIMLIB_ALL_IMAGES && (image < 1 || image > w->hdr.image_count)) return WIMLIB_ERR_INVALID_IMAGE; - if (image == WIM_ALL_IMAGES) - DEBUG("Writing all images to `%s'.", path); + if (w->hdr.total_parts != 1) { + ERROR("Cannot call wimlib_write() on part of a split WIM"); + return WIMLIB_ERR_SPLIT_UNSUPPORTED; + } + + ret = begin_write(w, path, write_flags); + if (ret != 0) + goto out; + + ret = write_wim_streams(w, image, write_flags, num_threads, + progress_func); + if (ret != 0) + goto out; + + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_BEGIN, NULL); + + ret = for_image(w, image, write_metadata_resource); + if (ret != 0) + goto out; + + if (progress_func) + progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_END, NULL); + + ret = finish_write(w, image, write_flags, progress_func); +out: + close_wim_writable(w); + DEBUG("wimlib_write(path=%s) = %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; +} + +/* + * 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; + bool found_modified_image; + + DEBUG("Overwriting `%s' 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. */ + if (w->hdr.integrity.offset != 0 && + w->hdr.integrity.offset < w->hdr.xml_res_entry.offset) { + ERROR("Didn't expect the integrity table to be before the XML data"); + return WIMLIB_ERR_RESOURCE_ORDER; + } + + if (w->hdr.lookup_table_res_entry.offset > w->hdr.xml_res_entry.offset) { + ERROR("Didn't expect the lookup table to be after the XML data"); + return WIMLIB_ERR_RESOURCE_ORDER; + } + + + if (w->hdr.integrity.offset) + old_wim_end = w->hdr.integrity.offset + w->hdr.integrity.size; else - DEBUG("Writing image %d to `%s'.", image, path); + old_wim_end = w->hdr.xml_res_entry.offset + w->hdr.xml_res_entry.size; - ret = begin_write(w, path, flags); + 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. */ + old_wim_end = w->hdr.lookup_table_res_entry.offset + + w->hdr.lookup_table_res_entry.size; + write_flags |= WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE | + WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML; + } + INIT_LIST_HEAD(&stream_list); + ret = wim_find_new_streams(w, old_wim_end, &stream_list); if (ret != 0) - goto done; + return ret; - for_lookup_table_entry(w->lookup_table, zero_out_refcnts, NULL); + ret = open_wim_writable(w, w->filename, false, + (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) != 0); + if (ret != 0) + return ret; - ret = for_image(w, image, write_file_resources); + ret = lock_wim(w, w->out_fp); if (ret != 0) { - ERROR("Failed to write WIM file resources to `%s'", path); - goto done; + fclose(w->out_fp); + w->out_fp = NULL; + return ret; } - ret = for_image(w, image, write_metadata_resource); + if (fseeko(w->out_fp, old_wim_end, SEEK_SET) != 0) { + ERROR_WITH_ERRNO("Can't seek to end of WIM"); + fclose(w->out_fp); + w->out_fp = NULL; + w->wim_locked = 0; + return WIMLIB_ERR_WRITE; + } + + if (!list_empty(&stream_list)) { + DEBUG("Writing newly added streams (offset = %"PRIu64")", + old_wim_end); + ret = write_stream_list(&stream_list, w->out_fp, + wimlib_get_compression_type(w), + write_flags, num_threads, + progress_func); + if (ret != 0) + goto out_ftruncate; + } else { + DEBUG("No new streams were added"); + } + + found_modified_image = false; + for (int i = 0; i < w->hdr.image_count; i++) { + if (!found_modified_image) + found_modified_image = w->image_metadata[i].modified; + if (found_modified_image) { + select_wim_image(w, i + 1); + ret = write_metadata_resource(w); + if (ret != 0) + goto out_ftruncate; + } + } + write_flags |= WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE; + ret = finish_write(w, WIMLIB_ALL_IMAGES, write_flags, + progress_func); +out_ftruncate: + close_wim_writable(w); + if (ret != 0 && !(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) { + WARNING("Truncating `%s' 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)truncate(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 `%s' via a temporary file", w->filename); + + /* Write the WIM to a temporary file in the same directory as the + * original WIM. */ + wim_name_len = strlen(w->filename); + char tmpfile[wim_name_len + 10]; + memcpy(tmpfile, w->filename, wim_name_len); + randomize_char_array_with_alnum(tmpfile + wim_name_len, 9); + tmpfile[wim_name_len + 9] = '\0'; + ret = wimlib_write(w, tmpfile, WIMLIB_ALL_IMAGES, + write_flags | WIMLIB_WRITE_FLAG_FSYNC, + num_threads, progress_func); if (ret != 0) { - ERROR("Failed to write WIM image metadata to `%s'", path); - goto done; + ERROR("Failed to write the WIM file `%s'", tmpfile); + goto err; } - ret = finish_write(w, image, flags, 1); + DEBUG("Renaming `%s' to `%s'", tmpfile, w->filename); -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; - } - w->out_fp = NULL; + /* Rename the new file to the old file .*/ + if (rename(tmpfile, w->filename) != 0) { + ERROR_WITH_ERRNO("Failed to rename `%s' to `%s'", + tmpfile, w->filename); + ret = WIMLIB_ERR_RENAME; + goto err; + } + + if (progress_func) { + union wimlib_progress_info progress; + progress.rename.from = tmpfile; + progress.rename.to = w->filename; + progress_func(WIMLIB_PROGRESS_MSG_RENAME, &progress); + } + + /* Close the original WIM file that was opened for reading. */ + if (w->fp != NULL) { + fclose(w->fp); + w->fp = NULL; + } + + /* Re-open the WIM read-only. */ + w->fp = fopen(w->filename, "rb"); + if (w->fp == NULL) { + ret = WIMLIB_ERR_REOPEN; + WARNING_WITH_ERRNO("Failed to re-open `%s' read-only", + w->filename); + FREE(w->filename); + w->filename = NULL; } return ret; +err: + /* Remove temporary file. */ + if (unlink(tmpfile) != 0) + WARNING_WITH_ERRNO("Failed to remove `%s'", tmpfile); + 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) +{ + write_flags &= WIMLIB_WRITE_MASK_PUBLIC; + + if (!w->filename) + return WIMLIB_ERR_NO_FILENAME; + + if (w->hdr.total_parts != 1) { + ERROR("Cannot modify a split WIM"); + return WIMLIB_ERR_SPLIT_UNSUPPORTED; + } + + 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); }