From c5746b5e79df3d5c129f6185cf5fa130ab0512df Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 20 Dec 2013 01:26:04 -0600 Subject: [PATCH] Add read_stream_list() --- include/wimlib/lookup_table.h | 50 +- include/wimlib/resource.h | 14 + src/lookup_table.c | 2 +- src/resource.c | 921 +++++++++++++++++++++++----------- 4 files changed, 655 insertions(+), 332 deletions(-) diff --git a/include/wimlib/lookup_table.h b/include/wimlib/lookup_table.h index a22ed3d1..bc765ca8 100644 --- a/include/wimlib/lookup_table.h +++ b/include/wimlib/lookup_table.h @@ -49,50 +49,50 @@ struct ntfs_location { * * If we open a WIM and read its lookup table, the location is set to * RESOURCE_IN_WIM since all the streams will initially be located in the WIM. - * However, to deal with problems such as image capture and image mount, we - * allow the actual location of the stream to be somewhere else, such as an - * external file. + * However, to handle situations such as image capture and image mount, we allow + * the actual location of the stream to be somewhere else, such as an external + * file. */ enum resource_location { - /* The lookup table entry does not correspond to a stream (this state - * should exist only temporarily) */ + /* The lookup table entry does not yet correspond to a stream; this is a + * temporary state only. */ RESOURCE_NONEXISTENT = 0, - /* The stream resource is located in a WIM file. The WIMStruct for the - * WIM file will be pointed to by the @wim member. The compression type - * of the resource will be cached in @compression_type, and the pipable - * status of the resource will be cached in @pipable. */ + /* The stream is located in a resource in a WIM file identified by the + * `struct wim_resource_spec' pointed to by @rspec. @offset_in_res + * identifies the offset at which this particular stream begins in the + * uncompressed data of the resource; this is normally 0, but in general + * a WIM resource may contain multiple streams. */ RESOURCE_IN_WIM, - /* The stream resource is located in an external file. The name of the - * file will be provided by @file_on_disk member. - * - * Note: On Windows @file_on_disk may actually specify a named data - * stream. */ + /* The stream is located in the external file named by @file_on_disk. + * On Windows, @file_on_disk may actually specify a named data stream. + */ RESOURCE_IN_FILE_ON_DISK, - /* The stream resource is directly attached in an in-memory buffer - * pointed to by @attached_buffer. */ + /* The stream is directly attached in the in-memory buffer pointed to by + * @attached_buffer. */ RESOURCE_IN_ATTACHED_BUFFER, #ifdef WITH_FUSE - /* The stream resource is located in an external file in the staging - * directory for a read-write mount. */ + /* The stream is located in the external file named by + * @staging_file_name, located in the staging directory for a read-write + * mount. */ RESOURCE_IN_STAGING_FILE, #endif #ifdef WITH_NTFS_3G - /* The stream resource is located in an NTFS volume. It is identified - * by volume, filename, data stream name, and by whether it is a reparse - * point or not. @ntfs_loc points to a structure containing this - * information. */ + /* The stream is located in an NTFS volume. It is identified by volume, + * filename, data stream name, and by whether it is a reparse point or + * not. @ntfs_loc points to a structure containing this information. + * */ RESOURCE_IN_NTFS_VOLUME, #endif #ifdef __WIN32__ - /* Windows only: the file is on disk in the file named @file_on_disk, - * but the file is encrypted and must be read using special functions. - * */ + /* Windows only: the stream is located in the external file named by + * @file_on_disk, but the file is encrypted and must be read using the + * appropriate Windows API. */ RESOURCE_WIN32_ENCRYPTED, #endif diff --git a/include/wimlib/resource.h b/include/wimlib/resource.h index 8e781c2e..249b0bc8 100644 --- a/include/wimlib/resource.h +++ b/include/wimlib/resource.h @@ -178,6 +178,20 @@ read_stream_prefix(const struct wim_lookup_table_entry *lte, u64 size, consume_data_callback_t cb, u32 in_chunk_size, void *ctx_or_buf, int flags); +/* Functions to read a list of resources. */ + +typedef int (*read_stream_list_begin_stream_t)(struct wim_lookup_table_entry *lte, void *ctx); +typedef int (*read_stream_list_end_stream_t)(struct wim_lookup_table_entry *lte, void *ctx); + +extern int +read_stream_list(struct list_head *stream_list, + size_t list_head_offset, + read_stream_list_begin_stream_t begin_stream, + consume_data_callback_t consume_chunk, + read_stream_list_end_stream_t end_stream, + u32 cb_chunk_size, + void *cb_ctx); + /* Functions to extract a resource. */ extern int diff --git a/src/lookup_table.c b/src/lookup_table.c index 496cc8ee..43287341 100644 --- a/src/lookup_table.c +++ b/src/lookup_table.c @@ -381,7 +381,7 @@ sort_stream_list_by_sequential_order(struct list_head *stream_list, array_size = num_streams * sizeof(array[0]); array = MALLOC(array_size); - if (!array) + if (array == NULL) return WIMLIB_ERR_NOMEM; cur = stream_list->next; for (i = 0; i < num_streams; i++) { diff --git a/src/resource.c b/src/resource.c index 3b5857da..1539460e 100644 --- a/src/resource.c +++ b/src/resource.c @@ -113,295 +113,287 @@ decompress(const void *cchunk, unsigned clen, void *uchunk, unsigned ulen, } } -/* Read data from a compressed WIM resource. Assumes parameters were already - * verified by read_partial_wim_resource(). */ +struct data_range { + u64 offset; + u64 size; +}; + +/* Alternate chunk table format for resources with WIM_RESHDR_FLAG_CONCAT set. + */ +struct alt_chunk_table_header_disk { + /* Uncompressed size of the resource. */ + le64 res_usize; + + /* Number of bytes each compressed chunk decompresses into, except + * possibly the last which decompresses into the remainder. */ + le32 chunk_size; + + /* ??? */ + le32 unknown; + + /* This header is directly followed by a table of compressed sizes of + * the chunks. */ +} _packed_attribute; + +/* Read data from a compressed WIM resource. */ static int read_compressed_wim_resource(const struct wim_resource_spec * const rspec, - const u64 size, const consume_data_callback_t cb, - const u32 cb_chunk_size, void * const ctx_or_buf, - const int flags, const u64 offset) + const struct data_range * const ranges, + const size_t num_ranges, + const consume_data_callback_t cb, + void * const cb_ctx, + const bool raw_chunks_mode) { int ret; int errno_save; - const u32 orig_chunk_size = rspec->cchunk_size; - const u32 orig_chunk_order = bsr32(orig_chunk_size); + u64 *chunk_offsets = NULL; + u8 *ubuf = NULL; + void *cbuf = NULL; + bool chunk_offsets_malloced = false; + bool ubuf_malloced = false; + bool cbuf_malloced = false; + + /* Sanity checks */ + wimlib_assert(rspec != NULL); + wimlib_assert(rspec->ctype != WIMLIB_COMPRESSION_TYPE_NONE); + wimlib_assert(is_power_of_2(rspec->cchunk_size)); + wimlib_assert(cb != NULL); + wimlib_assert(num_ranges != 0); + for (size_t i = 0; i < num_ranges; i++) { + wimlib_assert(ranges[i].size != 0); + wimlib_assert(ranges[i].offset + ranges[i].size >= ranges[i].size); + wimlib_assert(ranges[i].offset + ranges[i].size <= rspec->uncompressed_size); + } + for (size_t i = 0; i < num_ranges - 1; i++) + wimlib_assert(ranges[i].offset + ranges[i].size <= ranges[i + 1].offset); - wimlib_assert(is_power_of_2(orig_chunk_size)); + /* Get the offsets of the first and last bytes of the read. */ + const u64 first_offset = ranges[0].offset; + const u64 last_offset = ranges[num_ranges - 1].offset + ranges[num_ranges - 1].size - 1; - /* Handle the trivial case. */ - if (size == 0) - return 0; + /* Get the file descriptor for the WIM. */ + struct filedes * const in_fd = &rspec->wim->in_fd; - if (rspec->ctype == WIMLIB_COMPRESSION_TYPE_LZMS) { - /* TODO */ + /* Determine if we're reading a pipable resource from a pipe or not. */ + const bool is_pipe_read = !filedes_is_seekable(in_fd); - unsigned clen = rspec->size_in_wim; - unsigned ulen = rspec->uncompressed_size; - unsigned lzms_offset; + /* Determine if the chunk table is in an altenate format. */ + const bool alt_chunk_table = (rspec->flags & WIM_RESHDR_FLAG_CONCAT) && !is_pipe_read; - fprintf(stderr, "clen=%u, ulen=%u, offset=%lu\n", clen, ulen, - rspec->offset_in_wim); + /* Get the maximum size of uncompressed chunks in this resource, which + * we require be a power of 2. */ + u32 chunk_size; + u64 cur_read_offset = rspec->offset_in_wim; + if (alt_chunk_table) { + /* Alternate chunk table format. */ + struct alt_chunk_table_header_disk hdr; - u8 *cbuf = MALLOC(clen); - u8 *ubuf = MALLOC(ulen); + ret = full_pread(in_fd, &hdr, sizeof(hdr), cur_read_offset); + if (ret) + goto read_error; + cur_read_offset += sizeof(hdr); + chunk_size = le32_to_cpu(hdr.chunk_size); - ret = full_pread(&rspec->wim->in_fd, - cbuf, clen, rspec->offset_in_wim); - if (ret) { - ERROR_WITH_ERRNO("Can't read compressed data"); - goto out_free_bufs; + if (!is_power_of_2(chunk_size)) { + ERROR("Invalid compressed resource: " + "expected power-of-2 chunk size (got %u)", chunk_size); + ret = WIMLIB_ERR_INVALID_CHUNK_SIZE; + goto out_free_memory; } + } else { + chunk_size = rspec->cchunk_size; + } + const u32 chunk_order = bsr32(chunk_size); - if (clen <= rspec->cchunk_size) - lzms_offset = 0; - else - lzms_offset = 20; + /* Calculate the total number of chunks the resource is divided into. */ + const u64 num_chunks = (rspec->uncompressed_size + chunk_size - 1) >> chunk_order; - ret = wimlib_lzms_decompress(cbuf + lzms_offset, - clen - lzms_offset, - ubuf, ulen); - if (ret) { - ERROR("LZMS decompression error."); - errno = EINVAL; - ret = WIMLIB_ERR_DECOMPRESSION; - goto out_free_bufs; - } - if (cb) { - u32 chunk_size; - for (u64 i = offset; i < offset + size; i += chunk_size) { - chunk_size = min(offset + size - i, cb_chunk_size); - ret = cb(&ubuf[i], chunk_size, ctx_or_buf); - if (ret) - goto out_free_bufs; - } - } else { - memcpy(ctx_or_buf, &ubuf[offset], size); - } - ret = 0; - out_free_bufs: - FREE(ubuf); - FREE(cbuf); - return ret; - } + /* Calculate the 0-based indices of the first and last chunks containing + * data that needs to be passed to the callback. */ + const u64 first_needed_chunk = first_offset >> chunk_order; + const u64 last_needed_chunk = last_offset >> chunk_order; - u64 *chunk_offsets = NULL; - u8 *out_buf = NULL; - u8 *tmp_buf = NULL; - void *compressed_buf = NULL; - bool chunk_offsets_malloced = false; - bool out_buf_malloced = false; - bool tmp_buf_malloced = false; - bool compressed_buf_malloced = false; + /* Calculate the 0-based index of the first chunk that actually needs to + * be read. This is normally first_needed_chunk, but for pipe reads we + * must always start from the 0th chunk. */ + const u64 read_start_chunk = (is_pipe_read ? 0 : first_needed_chunk); - /* Get the file descriptor for the WIM. */ - struct filedes * const in_fd = &rspec->wim->in_fd; + /* Calculate the number of chunk offsets that are needed for the chunks + * being read. */ + const u64 num_needed_chunk_offsets = + last_needed_chunk - read_start_chunk + 1 + + (last_needed_chunk < num_chunks - 1); - /* Determine if we're reading a pipable resource from a pipe or not. */ - const bool is_pipe_read = !filedes_is_seekable(in_fd); + /* Calculate the number of entries in the chunk table. Normally, it's + * one less than the number of chunks, since the first chunk has no + * entry. But in the alternate chunk table format, the chunk entries + * contain chunk sizes, not offsets, and there is one per chunk. */ + const u64 num_chunk_entries = (alt_chunk_table ? num_chunks : num_chunks - 1); - /* Calculate the number of chunks the resource is divided into. */ - const u64 num_chunks = (rspec->uncompressed_size + orig_chunk_size - 1) >> orig_chunk_order; + /* Set the size of each chunk table entry based on the resource's + * uncompressed size. XXX: Does the alternate chunk table really + * always have 4-byte entries? */ + const u64 chunk_entry_size = + (rspec->uncompressed_size > (1ULL << 32) && !alt_chunk_table) + ? 8 : 4; - /* Calculate the 0-based index of the chunk at which the read starts. - */ - const u64 start_chunk = offset >> orig_chunk_order; + /* Calculate the size of the chunk table in bytes. */ + const u64 chunk_table_size = num_chunk_entries * chunk_entry_size; - /* For pipe reads, we always must start from the 0th chunk. */ - const u64 actual_start_chunk = (is_pipe_read ? 0 : start_chunk); + /* Includes header */ + const u64 chunk_table_full_size = + (alt_chunk_table) ? chunk_table_size + sizeof(struct alt_chunk_table_header_disk) + : chunk_table_size; - /* Calculate the offset, within the start chunk, of the first byte of - * the read. */ - const u32 start_offset_in_chunk = offset & (orig_chunk_size - 1); + if (!is_pipe_read) { + /* Read the needed chunk table entries into memory and use them + * to initialize the chunk_offsets array. */ + + u64 first_chunk_entry_to_read; + u64 last_chunk_entry_to_read; + + if (alt_chunk_table) { + /* The alternate chunk table contains chunk sizes, not + * offsets, so we always must read all preceding entries + * in order to determine offsets. */ + first_chunk_entry_to_read = 0; + last_chunk_entry_to_read = last_needed_chunk; + } else { + /* Here we must account for the fact that the first + * chunk has no explicit chunk table entry. */ - /* Calculate the index of the chunk that contains the last byte of the - * read. */ - const u64 end_chunk = (offset + size - 1) >> orig_chunk_order; + if (read_start_chunk == 0) + first_chunk_entry_to_read = 0; + else + first_chunk_entry_to_read = read_start_chunk - 1; - /* Calculate the offset, within the end chunk, of the last byte of the - * read. */ - const u32 end_offset_in_chunk = (offset + size - 1) & (orig_chunk_size - 1); + if (last_needed_chunk == 0) + last_chunk_entry_to_read = 0; + else + last_chunk_entry_to_read = last_needed_chunk - 1; - /* Calculate the number of entries in the chunk table; it's one less - * than the number of chunks, since the first chunk has no entry. */ - const u64 num_chunk_entries = num_chunks - 1; + if (last_needed_chunk < num_chunks - 1) + last_chunk_entry_to_read++; + } - /* Set the size of each chunk table entry based on the resource's - * uncompressed size. */ - const u64 chunk_entry_size = (rspec->uncompressed_size > (1ULL << 32)) ? 8 : 4; + const u64 num_chunk_entries_to_read = + last_chunk_entry_to_read - first_chunk_entry_to_read + 1; - /* Calculate the size, in bytes, of the full chunk table. */ - const u64 chunk_table_size = num_chunk_entries * chunk_entry_size; + const u64 chunk_offsets_alloc_size = + max(num_chunk_entries_to_read, + num_needed_chunk_offsets) * sizeof(chunk_offsets[0]); - /* Current offset to read from. */ - u64 cur_read_offset = rspec->offset_in_wim; - if (!is_pipe_read) { - /* Read the chunk table into memory. */ - - /* Calculate the number of chunk entries are actually needed to - * read the requested part of the resource. Include an entry - * for the first chunk even though that doesn't exist in the - * on-disk table, but take into account that if the last chunk - * required for the read is not the last chunk of the resource, - * an extra chunk entry is needed so that the compressed size of - * the last chunk of the read can be determined. */ - const u64 num_alloc_chunk_entries = end_chunk - start_chunk + - 1 + (end_chunk != num_chunks - 1); - - /* Allocate a buffer to hold a subset of the chunk table. It - * will only contain offsets for the chunks that are actually - * needed for this read. For speed, allocate the buffer on the - * stack unless it's too large. */ - if ((size_t)(num_alloc_chunk_entries * sizeof(u64)) != - (num_alloc_chunk_entries * sizeof(u64))) + if ((size_t)chunk_offsets_alloc_size != chunk_offsets_alloc_size) goto oom; - if (num_alloc_chunk_entries <= STACK_MAX / sizeof(u64)) { - chunk_offsets = alloca(num_alloc_chunk_entries * sizeof(u64)); + if (chunk_offsets_alloc_size <= STACK_MAX) { + chunk_offsets = alloca(chunk_offsets_alloc_size); } else { - chunk_offsets = MALLOC(num_alloc_chunk_entries * sizeof(u64)); + chunk_offsets = MALLOC(chunk_offsets_alloc_size); if (chunk_offsets == NULL) goto oom; chunk_offsets_malloced = true; } - /* Set the implicit offset of the first chunk if it's included - * in the needed chunks. */ - if (start_chunk == 0) - chunk_offsets[0] = 0; - - /* Calculate the index of the first needed entry in the chunk - * table. */ - const u64 start_table_idx = (start_chunk == 0) ? - 0 : start_chunk - 1; - - /* Calculate the number of entries that need to be read from the - * chunk table. */ - const u64 num_needed_chunk_entries = (start_chunk == 0) ? - num_alloc_chunk_entries - 1 : num_alloc_chunk_entries; - - /* Calculate the number of bytes of data that need to be read - * from the chunk table. */ - const size_t chunk_table_needed_size = - num_needed_chunk_entries * chunk_entry_size; - - /* Calculate the byte offset, in the WIM file, of the first - * chunk table entry to read. Take into account that if the WIM - * file is in the special "pipable" format, then the chunk table - * is at the end of the resource, not the beginning. */ + const size_t chunk_table_size_to_read = + num_chunk_entries_to_read * chunk_entry_size; + const u64 file_offset_of_needed_chunk_entries = - rspec->offset_in_wim - + (start_table_idx * chunk_entry_size) + cur_read_offset + + (first_chunk_entry_to_read * chunk_entry_size) + (rspec->is_pipable ? (rspec->size_in_wim - chunk_table_size) : 0); - /* Read the needed chunk table entries into the end of the - * chunk_offsets buffer. */ - void * const chunk_tab_data = (u8*)&chunk_offsets[num_alloc_chunk_entries] - - chunk_table_needed_size; - ret = full_pread(in_fd, chunk_tab_data, chunk_table_needed_size, + void * const chunk_table_data = + (u8*)chunk_offsets + + chunk_offsets_alloc_size - + chunk_table_size_to_read; + + ret = full_pread(in_fd, chunk_table_data, chunk_table_size, file_offset_of_needed_chunk_entries); if (ret) goto read_error; /* Now fill in chunk_offsets from the entries we have read in - * chunk_tab_data. Careful: chunk_offsets aliases - * chunk_tab_data, which breaks C's aliasing rules when we read - * 32-bit integers and store 64-bit integers. But since the - * operations are safe as long as the compiler doesn't mess with - * their order, we use the gcc may_alias extension to tell the - * compiler that loads from the 32-bit integers may alias stores - * to the 64-bit integers. */ - { - typedef le64 __attribute__((may_alias)) aliased_le64_t; - typedef le32 __attribute__((may_alias)) aliased_le32_t; - u64 * const chunk_offsets_p = chunk_offsets + (start_chunk == 0); - u64 i; + * chunk_tab_data. We break aliasing rules here to avoid having + * to allocate yet another array. */ + typedef le64 __attribute__((may_alias)) aliased_le64_t; + typedef le32 __attribute__((may_alias)) aliased_le32_t; + u64 * chunk_offsets_p = chunk_offsets; + + if (alt_chunk_table) { + u64 cur_offset = 0; + aliased_le32_t *raw_entries = chunk_table_data; + + for (size_t i = 0; i < num_chunk_entries_to_read; i++) { + u32 entry = le32_to_cpu(raw_entries[i]); + if (i >= read_start_chunk) + *chunk_offsets_p++ = cur_offset; + cur_offset += entry; + } + } else { + if (read_start_chunk == 0) + *chunk_offsets_p++ = 0; if (chunk_entry_size == 4) { - aliased_le32_t *raw_entries = (aliased_le32_t*)chunk_tab_data; - for (i = 0; i < num_needed_chunk_entries; i++) - chunk_offsets_p[i] = le32_to_cpu(raw_entries[i]); + aliased_le32_t *raw_entries = chunk_table_data; + for (size_t i = 0; i < num_chunk_entries_to_read; i++) + *chunk_offsets_p++ = le32_to_cpu(raw_entries[i]); } else { - aliased_le64_t *raw_entries = (aliased_le64_t*)chunk_tab_data; - for (i = 0; i < num_needed_chunk_entries; i++) - chunk_offsets_p[i] = le64_to_cpu(raw_entries[i]); + aliased_le64_t *raw_entries = chunk_table_data; + for (size_t i = 0; i < num_chunk_entries_to_read; i++) + *chunk_offsets_p++ = le64_to_cpu(raw_entries[i]); } } /* Set offset to beginning of first chunk to read. */ cur_read_offset += chunk_offsets[0]; if (rspec->is_pipable) - cur_read_offset += start_chunk * sizeof(struct pwm_chunk_hdr); + cur_read_offset += read_start_chunk * sizeof(struct pwm_chunk_hdr); else cur_read_offset += chunk_table_size; } - /* If using a callback function, allocate a temporary buffer that will - * hold data being passed to it. If writing directly to a buffer - * instead, arrange to write data directly into it. */ - size_t out_buf_size; - u8 *out_buf_end, *out_p; - if (cb) { - out_buf_size = max(cb_chunk_size, orig_chunk_size); - if (out_buf_size <= STACK_MAX) { - out_buf = alloca(out_buf_size); - } else { - out_buf = MALLOC(out_buf_size); - if (out_buf == NULL) - goto oom; - out_buf_malloced = true; - } + /* Allocate buffer for holding the uncompressed data of each chunk. */ + if (chunk_size <= STACK_MAX) { + ubuf = alloca(chunk_size); } else { - out_buf_size = size; - out_buf = ctx_or_buf; + ubuf = MALLOC(chunk_size); + if (ubuf == NULL) + goto oom; + ubuf_malloced = true; } - out_buf_end = out_buf + out_buf_size; - out_p = out_buf; /* Unless the raw compressed data was requested, allocate a temporary * buffer for reading compressed chunks, each of which can be at most - * @orig_chunk_size - 1 bytes. This excludes compressed chunks that are - * a full @orig_chunk_size bytes, which are actually stored - * uncompressed. */ - if (!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS)) { - if (orig_chunk_size - 1 <= STACK_MAX) { - compressed_buf = alloca(orig_chunk_size - 1); + * @chunk_size - 1 bytes. This excludes compressed chunks that are a + * full @chunk_size bytes, which are actually stored uncompressed. */ + if (!raw_chunks_mode) { + if (chunk_size - 1 <= STACK_MAX) { + cbuf = alloca(chunk_size - 1); } else { - compressed_buf = MALLOC(orig_chunk_size - 1); - if (compressed_buf == NULL) + cbuf = MALLOC(chunk_size - 1); + if (cbuf == NULL) goto oom; - compressed_buf_malloced = true; + cbuf_malloced = true; } } - /* Allocate yet another temporary buffer, this one for decompressing - * chunks for which only part of the data is needed. */ - if (start_offset_in_chunk != 0 || - (end_offset_in_chunk != orig_chunk_size - 1 && - offset + size != rspec->uncompressed_size)) - { - if (orig_chunk_size <= STACK_MAX) { - tmp_buf = alloca(orig_chunk_size); - } else { - tmp_buf = MALLOC(orig_chunk_size); - if (tmp_buf == NULL) - goto oom; - tmp_buf_malloced = true; - } - } + /* Read and process each needed chunk. */ + const struct data_range *cur_range = ranges; + const struct data_range * const end_range = &ranges[num_ranges]; + u64 cur_range_pos = cur_range->offset; + u64 cur_range_end = cur_range->offset + cur_range->size; - /* Read, and possibly decompress, each needed chunk, either writing the - * data directly into the @ctx_or_buf buffer or passing it to the @cb - * callback function. */ - for (u64 i = actual_start_chunk; i <= end_chunk; i++) { + for (u64 i = read_start_chunk; i <= last_needed_chunk; i++) { /* Calculate uncompressed size of next chunk. */ u32 chunk_usize; - if ((i == num_chunks - 1) && (rspec->uncompressed_size & (orig_chunk_size - 1))) - chunk_usize = (rspec->uncompressed_size & (orig_chunk_size - 1)); + if ((i == num_chunks - 1) && (rspec->uncompressed_size & (chunk_size - 1))) + chunk_usize = (rspec->uncompressed_size & (chunk_size - 1)); else - chunk_usize = orig_chunk_size; + chunk_usize = chunk_size; /* Calculate compressed size of next chunk. */ u32 chunk_csize; @@ -416,13 +408,13 @@ read_compressed_wim_resource(const struct wim_resource_spec * const rspec, } else { if (i == num_chunks - 1) { chunk_csize = rspec->size_in_wim - - chunk_table_size - - chunk_offsets[i - start_chunk]; + chunk_table_full_size - + chunk_offsets[i - read_start_chunk]; if (rspec->is_pipable) chunk_csize -= num_chunks * sizeof(struct pwm_chunk_hdr); } else { - chunk_csize = chunk_offsets[i + 1 - start_chunk] - - chunk_offsets[i - start_chunk]; + chunk_csize = chunk_offsets[i + 1 - read_start_chunk] - + chunk_offsets[i - read_start_chunk]; } } if (chunk_csize == 0 || chunk_csize > chunk_usize) { @@ -434,106 +426,88 @@ read_compressed_wim_resource(const struct wim_resource_spec * const rspec, if (rspec->is_pipable) cur_read_offset += sizeof(struct pwm_chunk_hdr); - if (i >= start_chunk) { - /* Calculate how much of this chunk needs to be read. */ - u32 chunk_needed_size; - u32 start_offset = 0; - u32 end_offset = orig_chunk_size - 1; - - if (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS) { - chunk_needed_size = chunk_csize; - } else { - if (i == start_chunk) - start_offset = start_offset_in_chunk; + /* Uncompressed offsets */ + const u64 chunk_start_offset = i << chunk_order; + const u64 chunk_end_offset = chunk_start_offset + chunk_usize; - if (i == end_chunk) - end_offset = end_offset_in_chunk; + if (chunk_end_offset <= cur_range_pos) { - chunk_needed_size = end_offset + 1 - start_offset; - } + /* The next range does not require data in this chunk, + * so skip it. */ - if (chunk_csize == chunk_usize || - (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS)) - { - /* Read the raw chunk data. */ + cur_read_offset += chunk_csize; + if (is_pipe_read) { + u8 dummy; - ret = full_pread(in_fd, - out_p, - chunk_needed_size, - cur_read_offset + start_offset); + ret = full_pread(in_fd, &dummy, 1, cur_read_offset - 1); if (ret) goto read_error; - } else { - /* Read and decompress the chunk. */ + } + } else { - u8 *target; + /* Read the chunk and feed data to the callback + * function. */ + u8 *cb_buf; - ret = full_pread(in_fd, - compressed_buf, - chunk_csize, - cur_read_offset); - if (ret) - goto read_error; - - if (chunk_needed_size == chunk_usize) - target = out_p; - else - target = tmp_buf; + ret = full_pread(in_fd, + cbuf, + chunk_csize, + cur_read_offset); + if (ret) + goto read_error; - ret = decompress(compressed_buf, + if (chunk_csize != chunk_usize && !raw_chunks_mode) { + ret = decompress(cbuf, chunk_csize, - target, + ubuf, chunk_usize, rspec->ctype, - orig_chunk_size); + chunk_size); if (ret) { ERROR("Failed to decompress data!"); ret = WIMLIB_ERR_DECOMPRESSION; errno = EINVAL; goto out_free_memory; } - if (chunk_needed_size != chunk_usize) - memcpy(out_p, tmp_buf + start_offset, - chunk_needed_size); + cb_buf = ubuf; + } else { + cb_buf = cbuf; } + cur_read_offset += chunk_csize; + + /* At least one range requires data in this chunk. + * However, the data fed to the callback function must + * not overlap range boundaries. */ + do { + size_t start, end, size; + + start = cur_range_pos - chunk_start_offset; + end = min(cur_range_end, chunk_end_offset) - chunk_start_offset; + size = end - start; + + if (raw_chunks_mode) + ret = (*cb)(&cb_buf[0], chunk_csize, cb_ctx); + else + ret = (*cb)(&cb_buf[start], size, cb_ctx); + + if (ret) + goto out_free_memory; - out_p += chunk_needed_size; - - if (cb) { - /* Feed the data to the callback function. */ - - if (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS) { - ret = cb(out_buf, out_p - out_buf, ctx_or_buf); - if (ret) - goto out_free_memory; - out_p = out_buf; - } else if (i == end_chunk || out_p == out_buf_end) { - size_t bytes_sent; - const u8 *p; - - for (p = out_buf; p != out_p; p += bytes_sent) { - bytes_sent = min(cb_chunk_size, out_p - p); - ret = cb(p, bytes_sent, ctx_or_buf); - if (ret) - goto out_free_memory; + cur_range_pos += size; + if (cur_range_pos == cur_range_end) { + if (++cur_range == end_range) { + cur_range_pos = ~0ULL; + } else { + cur_range_pos = cur_range->offset; + cur_range_end = cur_range->offset + cur_range->size; } - out_p = out_buf; } - } - cur_read_offset += chunk_csize; - } else { - u8 dummy; - - /* Skip data only. */ - cur_read_offset += chunk_csize; - ret = full_pread(in_fd, &dummy, 1, cur_read_offset - 1); - if (ret) - goto read_error; + } while (cur_range_pos < chunk_end_offset); } } if (is_pipe_read - && size == rspec->uncompressed_size + && last_offset == rspec->uncompressed_size - 1 && chunk_table_size) { u8 dummy; @@ -549,18 +523,16 @@ out_free_memory: errno_save = errno; if (chunk_offsets_malloced) FREE(chunk_offsets); - if (out_buf_malloced) - FREE(out_buf); - if (compressed_buf_malloced) - FREE(compressed_buf); - if (tmp_buf_malloced) - FREE(tmp_buf); + if (ubuf_malloced) + FREE(ubuf); + if (cbuf_malloced) + FREE(cbuf); errno = errno_save; return ret; oom: ERROR("Not enough memory available to read size=%"PRIu64" bytes " - "from compressed resource!", size); + "from compressed resource!", last_offset - first_offset + 1); errno = ENOMEM; ret = WIMLIB_ERR_NOMEM; goto out_free_memory; @@ -621,6 +593,71 @@ out: return ret; } +static int +bufferer_cb(const void *chunk, size_t size, void *_ctx) +{ + u8 **buf_p = _ctx; + + *buf_p = mempcpy(*buf_p, chunk, size); + return 0; +} + +struct rechunker_context { + u8 *buffer; + u32 buffer_filled; + u32 cb_chunk_size; + + const struct data_range *ranges; + size_t num_ranges; + size_t cur_range; + u64 range_bytes_remaining; + + consume_data_callback_t cb; + void *cb_ctx; +}; + +static int +rechunker_cb(const void *chunk, size_t size, void *_ctx) +{ + struct rechunker_context *ctx = _ctx; + const u8 *chunkptr = chunk; + size_t bytes_to_copy; + int ret; + + wimlib_assert(ctx->cur_range != ctx->num_ranges); + + while (size) { + bytes_to_copy = size; + + if (bytes_to_copy > ctx->cb_chunk_size - ctx->buffer_filled) + bytes_to_copy = ctx->cb_chunk_size - ctx->buffer_filled; + + if (bytes_to_copy > ctx->range_bytes_remaining - ctx->buffer_filled) + bytes_to_copy = ctx->range_bytes_remaining - ctx->buffer_filled; + + memcpy(&ctx->buffer[ctx->buffer_filled], chunkptr, bytes_to_copy); + + ctx->buffer_filled += bytes_to_copy; + chunkptr += bytes_to_copy; + size -= bytes_to_copy; + ctx->range_bytes_remaining -= bytes_to_copy; + + if (ctx->buffer_filled == ctx->cb_chunk_size || + ctx->range_bytes_remaining == 0) + { + ret = (*ctx->cb)(ctx->buffer, ctx->buffer_filled, ctx->cb_ctx); + if (ret) + return ret; + ctx->buffer_filled = 0; + + if (ctx->range_bytes_remaining == 0 && + ++ctx->cur_range != ctx->num_ranges) + ctx->range_bytes_remaining = ctx->ranges[ctx->cur_range].size; + } + } + return 0; +} + /* * read_partial_wim_resource()- * @@ -672,7 +709,7 @@ read_partial_wim_resource(const struct wim_lookup_table_entry *lte, wimlib_assert(!lte_is_partial(lte)); wimlib_assert(!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW_FULL)); wimlib_assert(cb_chunk_size == rspec->cchunk_size); - wimlib_assert(size == rspec->uncompressed_size); + wimlib_assert(size == lte->size); wimlib_assert(offset == 0); } else if (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_FULL) { /* Raw full mode: read must not overrun end of store size. */ @@ -682,7 +719,7 @@ read_partial_wim_resource(const struct wim_lookup_table_entry *lte, } else { /* Normal mode: read must not overrun end of original size. */ wimlib_assert(offset + size >= size && - lte->offset_in_res + offset + size <= rspec->uncompressed_size); + offset + size <= lte->size); } DEBUG("Reading WIM resource: %"PRIu64" @ +%"PRIu64"[+%"PRIu64"] " @@ -703,11 +740,67 @@ read_partial_wim_resource(const struct wim_lookup_table_entry *lte, cb, cb_chunk_size, ctx_or_buf, - offset + rspec->offset_in_wim); + rspec->offset_in_wim + lte->offset_in_res + offset); } else { - return read_compressed_wim_resource(rspec, size, cb, - cb_chunk_size, - ctx_or_buf, flags, offset + lte->offset_in_res); + bool raw_chunks; + struct data_range range; + consume_data_callback_t internal_cb; + void *internal_cb_ctx; + u8 *buf; + bool rechunker_buf_malloced = false; + struct rechunker_context *rechunker_ctx; + int ret; + + if (size == 0) + return 0; + + range.offset = lte->offset_in_res + offset; + range.size = size; + raw_chunks = !!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS); + + if (cb != NULL && + cb_chunk_size == rspec->cchunk_size && + !(rspec->flags & WIM_RESHDR_FLAG_CONCAT)) + { + internal_cb = cb; + internal_cb_ctx = ctx_or_buf; + } else if (cb == NULL) { + buf = ctx_or_buf; + internal_cb = bufferer_cb; + internal_cb_ctx = &buf; + } else { + rechunker_ctx = alloca(sizeof(struct rechunker_context)); + + if (cb_chunk_size <= STACK_MAX) { + rechunker_ctx->buffer = alloca(cb_chunk_size); + } else { + rechunker_ctx->buffer = MALLOC(cb_chunk_size); + if (rechunker_ctx->buffer == NULL) + return WIMLIB_ERR_NOMEM; + rechunker_buf_malloced = true; + } + rechunker_ctx->buffer_filled = 0; + rechunker_ctx->cb_chunk_size = cb_chunk_size; + + rechunker_ctx->ranges = ⦥ + rechunker_ctx->num_ranges = 1; + rechunker_ctx->cur_range = 0; + rechunker_ctx->range_bytes_remaining = range.size; + + rechunker_ctx->cb = cb; + rechunker_ctx->cb_ctx = ctx_or_buf; + + internal_cb = rechunker_cb; + internal_cb_ctx = rechunker_ctx; + } + + ret = read_compressed_wim_resource(rspec, &range, 1, + internal_cb, internal_cb_ctx, + raw_chunks); + if (rechunker_buf_malloced) + FREE(rechunker_ctx->buffer); + + return ret; } } @@ -928,6 +1021,222 @@ wim_reshdr_to_data(const struct wim_reshdr *reshdr, WIMStruct *wim, void **buf_r return wim_resource_spec_to_data(&rspec, buf_ret); } +struct read_stream_list_ctx { + read_stream_list_begin_stream_t begin_stream; + consume_data_callback_t consume_chunk; + read_stream_list_end_stream_t end_stream; + void *begin_stream_ctx; + void *consume_chunk_ctx; + void *end_stream_ctx; + struct wim_lookup_table_entry *cur_stream; + u64 cur_stream_offset; + struct wim_lookup_table_entry *final_stream; + size_t list_head_offset; +}; + +static int +read_stream_list_wrapper_cb(const void *chunk, size_t size, void *_ctx) +{ + struct read_stream_list_ctx *ctx = _ctx; + int ret; + + if (ctx->cur_stream_offset == 0) { + /* Starting a new stream. */ + ret = (*ctx->begin_stream)(ctx->cur_stream, ctx->begin_stream_ctx); + if (ret) + return ret; + } + + ret = (*ctx->consume_chunk)(chunk, size, ctx->consume_chunk_ctx); + if (ret) + return ret; + + ctx->cur_stream_offset += size; + + if (ctx->cur_stream_offset == ctx->cur_stream->size) { + /* Finished reading all the data for a stream; advance + * to the next one. */ + ret = (*ctx->end_stream)(ctx->cur_stream, ctx->end_stream_ctx); + if (ret) + return ret; + + if (ctx->cur_stream == ctx->final_stream) + return 0; + + struct list_head *cur = (struct list_head *) + ((u8*)ctx->cur_stream + ctx->list_head_offset); + struct list_head *next = cur->next; + + ctx->cur_stream = (struct wim_lookup_table_entry *) + ((u8*)next - ctx->list_head_offset); + + ctx->cur_stream_offset = 0; + } + return 0; +} + +/* + * Read a list of streams, each of which may be in any supported location (e.g. + * in a WIM or in an external file). Unlike read_stream_prefix() or the + * functions which call it, this function optimizes the case where multiple + * streams are packed into a single compressed WIM resource and reads them all + * consecutively, only decompressing the data one time. + * + * @stream_list + * List of streams (represented as `struct wim_lookup_table_entry's) to + * read. + * @list_head_offset + * Offset of the `struct list_head' within each `struct + * wim_lookup_table_entry' that makes up the @stream_list. + * @begin_stream + * Callback for starting to process a stream. + * @consume_chunk + * Callback for receiving a chunk of stream data. + * @end_stream + * Callback for finishing the processing of a stream. + * @cb_chunk_size + * Size of chunks to provide to @consume_chunk. For a given stream, all + * the chunks will be this size, except possibly the last which will be the + * remainder. + * @cb_ctx + * Parameter to pass to the callback functions. + * + * Returns 0 on success; a nonzero error code on failure. Failure can occur due + * to an error reading the data or due to an error status being returned by any + * of the callback functions. + */ +int +read_stream_list(struct list_head *stream_list, + size_t list_head_offset, + read_stream_list_begin_stream_t begin_stream, + consume_data_callback_t consume_chunk, + read_stream_list_end_stream_t end_stream, + u32 cb_chunk_size, + void *cb_ctx) +{ + int ret; + struct list_head *cur, *next; + struct wim_lookup_table_entry *lte; + + ret = sort_stream_list_by_sequential_order(stream_list, list_head_offset); + if (ret) + return ret; + + for (cur = stream_list->next, next = cur->next; + cur != stream_list; + cur = next, next = cur->next) + { + lte = (struct wim_lookup_table_entry*)((u8*)cur - list_head_offset); + + if (lte_is_partial(lte)) { + + struct wim_lookup_table_entry *lte_next, *lte_last; + struct list_head *next2; + size_t stream_count; + + /* The next stream is a proper sub-sequence of a WIM + * resource. See if there are other streams in the same + * resource that need to be read. Since + * sort_stream_list_by_sequential_order() sorted the + * streams by offset in the WIM, this can be determined + * by simply scanning forward in the list. */ + + lte_last = lte; + stream_count = 1; + for (next2 = next; + next2 != stream_list + && (lte_next = (struct wim_lookup_table_entry*) + ((u8*)next2 - list_head_offset), + lte_next->resource_location == RESOURCE_IN_WIM + && lte_next->rspec == lte->rspec); + next2 = next2->next) + { + lte_last = lte_next; + stream_count++; + } + if (stream_count > 1) { + /* Reading multiple streams combined into a + * single WIM resource. They are in the stream + * list, sorted by offset; @lte specifies the + * first stream in the resource that needs to be + * read and @lte_last specifies the last stream + * in the resource that needs to be read. */ + + next = next2; + + struct data_range ranges[stream_count]; + + { + struct list_head *next3; + size_t i; + struct wim_lookup_table_entry *lte_cur; + + next3 = cur; + for (i = 0; i < stream_count; i++) { + lte_cur = (struct wim_lookup_table_entry*) + ((u8*)next3 - list_head_offset); + ranges[i].offset = lte_cur->offset_in_res; + ranges[i].size = lte_cur->size; + next3 = next3->next; + } + } + + struct rechunker_context rechunker_ctx = { + .buffer = MALLOC(cb_chunk_size), + .buffer_filled = 0, + .cb_chunk_size = cb_chunk_size, + .ranges = ranges, + .num_ranges = stream_count, + .cur_range = 0, + .range_bytes_remaining = ranges[0].size, + .cb = consume_chunk, + .cb_ctx = cb_ctx, + }; + + if (rechunker_ctx.buffer == NULL) + return WIMLIB_ERR_NOMEM; + + struct read_stream_list_ctx ctx = { + .begin_stream = begin_stream, + .begin_stream_ctx = cb_ctx, + .consume_chunk = rechunker_cb, + .consume_chunk_ctx = &rechunker_ctx, + .end_stream = end_stream, + .end_stream_ctx = cb_ctx, + .cur_stream = lte, + .cur_stream_offset = 0, + .final_stream = lte_last, + .list_head_offset = list_head_offset, + }; + + ret = read_compressed_wim_resource(lte->rspec, + ranges, + stream_count, + read_stream_list_wrapper_cb, + &ctx, + false); + FREE(rechunker_ctx.buffer); + if (ret) + return ret; + continue; + } + } + ret = (*begin_stream)(lte, cb_ctx); + if (ret) + return ret; + + ret = read_stream_prefix(lte, lte->size, consume_chunk, + cb_chunk_size, cb_ctx, 0); + if (ret) + return ret; + + ret = (*end_stream)(lte, cb_ctx); + if (ret) + return ret; + } + return 0; +} + struct extract_ctx { SHA_CTX sha_ctx; consume_data_callback_t extract_chunk; -- 2.43.0