+
+static int
+main_writer_thread_cb(const void *chunk, size_t chunk_size, void *_ctx)
+{
+ struct main_writer_thread_ctx *ctx = _ctx;
+ int ret;
+ struct message *next_msg;
+
+ next_msg = ctx->next_msg;
+
+ sha1_update(&ctx->sha_ctx, chunk, chunk_size);
+
+ if (!next_msg) {
+ if (list_empty(&ctx->available_msgs)) {
+ ret = receive_compressed_chunks(ctx);
+ if (ret)
+ return ret;
+ }
+
+ wimlib_assert(!list_empty(&ctx->available_msgs));
+
+ next_msg = container_of(ctx->available_msgs.next,
+ struct message,
+ list);
+ list_del(&next_msg->list);
+ next_msg->complete = false;
+ next_msg->begin_chunk = ctx->next_chunk;
+ next_msg->num_chunks = min(MAX_CHUNKS_PER_MSG,
+ ctx->next_num_chunks - ctx->next_chunk);
+ ctx->next_chunk_in_msg = 0;
+ }
+
+ wimlib_assert(next_msg != NULL);
+ wimlib_assert(ctx->next_chunk_in_msg < next_msg->num_chunks);
+
+ next_msg->uncompressed_chunk_sizes[ctx->next_chunk_in_msg] = chunk_size;
+ memcpy(next_msg->uncompressed_chunks[ctx->next_chunk_in_msg],
+ chunk, chunk_size);
+
+ if (++ctx->next_chunk_in_msg == next_msg->num_chunks) {
+ shared_queue_put(ctx->res_to_compress_queue,
+ next_msg);
+ ctx->next_msg = NULL;
+ }
+ return 0;
+}
+
+static int
+submit_stream_for_compression(struct wim_lookup_table_entry *lte,
+ struct main_writer_thread_ctx *ctx)
+{
+ int ret;
+
+ sha1_init(&ctx->sha_ctx);
+ ctx->next_num_chunks = wim_resource_chunks(lte);
+ ret = read_resource_prefix(lte, wim_resource_size(lte),
+ main_writer_thread_cb, ctx, 0);
+ if (ret)
+ return ret;
+ ret = finalize_and_check_sha1(&ctx->sha_ctx, lte);
+ if (ret)
+ return ret;
+}
+
+/*
+ * 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 main_writer_thread_ctx *ctx)
+{
+ int ret;
+ struct list_head *stream_list;
+ struct wim_lookup_table_entry *lte;
+
+ ret = main_writer_thread_init_ctx(ctx);
+ if (ret)
+ goto out_destroy_ctx;
+
+ stream_list = ctx->stream_list;
+ while (!list_empty(stream_list)) {
+ lte = container_of(stream_list->next,
+ struct wim_lookup_table_entry,
+ write_streams_list);
+ list_del(<e->write_streams_list);
+ if (lte->unhashed && !lte->unique_size) {
+ struct wim_lookup_table_entry *tmp;
+ u32 orig_refcnt = lte->out_refcnt;
+
+ ret = hash_unhashed_stream(lte, ctx->lookup_table, &tmp);
+ if (ret)
+ goto out_destroy_ctx;
+ if (tmp != lte) {
+ lte = tmp;
+ if (orig_refcnt != tmp->out_refcnt) {
+ DEBUG("Discarding duplicate stream of length %"PRIu64,
+ wim_resource_size(lte));
+ goto skip_to_progress;
+ }
+ }
+ }
+
+ if (wim_resource_size(lte) < 1000 ||
+ ctx->out_ctype == WIMLIB_COMPRESSION_TYPE_NONE ||
+ (lte->resource_location == RESOURCE_IN_WIM &&
+ wimlib_get_compression_type(lte->wim) == ctx->out_ctype))
+ {
+ list_add(<e->write_streams_list,
+ &ctx->serial_streams);
+ } else {
+ ret = submit_stream_for_compression(lte, ctx);
+ if (ret)
+ goto out_destroy_ctx;
+ if (lte->unhashed) {
+ list_del(<e->unhashed_list);
+ lookup_table_insert(ctx->lookup_table, lte);
+ lte->unhashed = 0;
+ }
+ }
+ skip_to_progress:
+ do_write_streams_progress(ctx->progress,
+ ctx->progress_func,
+ wim_resource_size(lte));
+ }
+
+ while (!list_empty(&ctx->outstanding_streams)) {
+ ret = receive_compressed_chunks(ctx);
+ if (ret)
+ goto out_destroy_ctx;
+ }
+ ret = 0;
+out_destroy_ctx:
+ main_writer_thread_destroy_ctx(ctx);
+ return ret;
+}
+
+static long
+get_default_num_threads()
+{
+#ifdef __WIN32__
+ return win32_get_number_of_processors();
+#else
+ return sysconf(_SC_NPROCESSORS_ONLN);
+#endif
+}
+
+static int
+write_stream_list_parallel(struct list_head *stream_list,
+ struct wim_lookup_table *lookup_table,
+ 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 = get_default_num_threads();
+ if (nthreads < 1 || nthreads > UINT_MAX) {
+ WARNING("Could not determine number of processors! Assuming 1");
+ goto out_serial;
+ } else {
+ num_threads = nthreads;
+ }
+ }
+
+ progress->write_streams.num_threads = num_threads;
+
+ 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;
+
+ struct compressor_thread_params params;
+ params.res_to_compress_queue = &res_to_compress_queue;
+ params.compressed_res_queue = &compressed_res_queue;
+ params.compress = get_compress_func(out_ctype);
+
+ compressor_threads = MALLOC(num_threads * sizeof(pthread_t));
+ if (!compressor_threads) {
+ ret = WIMLIB_ERR_NOMEM;
+ goto out_destroy_compressed_res_queue;
+ }
+
+ for (unsigned i = 0; i < num_threads; i++) {
+ DEBUG("pthread_create thread %u", 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;
+ }
+ }
+
+ if (progress_func)
+ progress_func(WIMLIB_PROGRESS_MSG_WRITE_STREAMS, progress);
+
+ struct main_writer_thread_ctx ctx;
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.stream_list = stream_list;
+ ctx.lookup_table = lookup_table;
+ ctx.out_fp = out_fp;
+ ctx.out_ctype = out_ctype;
+ ctx.res_to_compress_queue = &res_to_compress_queue;
+ ctx.compressed_res_queue = &compressed_res_queue;
+ ctx.num_messages = queue_size;
+ ctx.write_flags = write_flags;
+ ctx.progress_func = progress_func;
+ ctx.progress = progress;
+ ret = main_writer_thread_proc(&ctx);
+out_join:
+ for (unsigned i = 0; i < num_threads; i++)
+ shared_queue_put(&res_to_compress_queue, NULL);
+
+ for (unsigned i = 0; i < num_threads; i++) {
+ if (pthread_join(compressor_threads[i], NULL)) {
+ WARNING_WITH_ERRNO("Failed to join compressor "
+ "thread %u", 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,
+ lookup_table,
+ out_fp,
+ out_ctype,
+ write_flags,
+ progress_func,
+ progress);
+
+}
+#endif
+
+/*
+ * 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,
+ struct wim_lookup_table *lookup_table,
+ FILE *out_fp, int out_ctype, int write_flags,
+ unsigned num_threads, wimlib_progress_func_t progress_func)
+{
+ struct wim_lookup_table_entry *lte;
+ size_t num_streams = 0;
+ u64 total_bytes = 0;
+ u64 total_compression_bytes = 0;
+ union wimlib_progress_info progress;
+ int ret;
+
+ if (list_empty(stream_list))
+ return 0;
+
+ /* Calculate the total size of the streams to be written. Note: this
+ * will be the uncompressed size, as we may not know the compressed size
+ * yet, and also this will assume that every unhashed stream will be
+ * written (which will not necessarily be the case). */
+ list_for_each_entry(lte, stream_list, write_streams_list) {
+ num_streams++;
+ total_bytes += wim_resource_size(lte);
+ if (out_ctype != WIMLIB_COMPRESSION_TYPE_NONE
+ && (wim_resource_compression_type(lte) != out_ctype ||
+ (write_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;
+ progress.write_streams._private = 0;
+
+#ifdef ENABLE_MULTITHREADED_COMPRESSION
+ if (total_compression_bytes >= 1000000 && num_threads != 1)
+ ret = write_stream_list_parallel(stream_list,
+ lookup_table,
+ out_fp,
+ out_ctype,
+ write_flags,
+ num_threads,
+ progress_func,
+ &progress);
+ else
+#endif
+ ret = write_stream_list_serial(stream_list,
+ lookup_table,
+ out_fp,
+ out_ctype,
+ write_flags,
+ progress_func,
+ &progress);
+ return ret;
+}
+
+struct stream_size_table {
+ struct hlist_head *array;
+ size_t num_entries;
+ size_t capacity;
+};
+
+static int
+init_stream_size_table(struct stream_size_table *tab, size_t capacity)
+{
+ tab->array = CALLOC(capacity, sizeof(tab->array[0]));
+ if (!tab->array)
+ return WIMLIB_ERR_NOMEM;
+ tab->num_entries = 0;
+ tab->capacity = capacity;
+ return 0;
+}
+
+static void
+destroy_stream_size_table(struct stream_size_table *tab)
+{
+ FREE(tab->array);
+}
+
+static int
+stream_size_table_insert(struct wim_lookup_table_entry *lte, void *_tab)
+{
+ struct stream_size_table *tab = _tab;
+ size_t pos;
+ struct wim_lookup_table_entry *hashed_lte;
+ struct hlist_node *tmp;
+
+ pos = hash_u64(wim_resource_size(lte)) % tab->capacity;
+ lte->unique_size = 1;
+ hlist_for_each_entry(hashed_lte, tmp, &tab->array[pos], hash_list_2) {
+ if (wim_resource_size(hashed_lte) == wim_resource_size(lte)) {
+ lte->unique_size = 0;
+ hashed_lte->unique_size = 0;
+ break;
+ }
+ }
+
+ hlist_add_head(<e->hash_list_2, &tab->array[pos]);
+ tab->num_entries++;
+ return 0;
+}
+
+
+struct lte_overwrite_prepare_args {
+ WIMStruct *wim;
+ off_t end_offset;
+ struct list_head stream_list;
+ struct stream_size_table stream_size_tab;
+};
+
+static int
+lte_overwrite_prepare(struct wim_lookup_table_entry *lte, void *arg)
+{
+ struct lte_overwrite_prepare_args *args = arg;
+
+ if (lte->resource_location == RESOURCE_IN_WIM &&
+ lte->wim == args->wim)
+ {
+ /* We can't do an in place overwrite on the WIM if there are
+ * streams after the XML data. */
+ if (lte->resource_entry.offset +
+ lte->resource_entry.size > args->end_offset)
+ {
+ #ifdef ENABLE_ERROR_MESSAGES
+ ERROR("The following resource is after the XML data:");
+ print_lookup_table_entry(lte, stderr);
+ #endif
+ return WIMLIB_ERR_RESOURCE_ORDER;
+ }
+ } else {
+ wimlib_assert(!(lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA));
+ list_add_tail(<e->write_streams_list, &args->stream_list);
+ }
+ lte->out_refcnt = lte->refcnt;
+ stream_size_table_insert(lte, &args->stream_size_tab);
+ return 0;
+}
+
+static int
+lte_set_output_res_entry(struct wim_lookup_table_entry *lte, void *_wim)
+{
+ if (lte->resource_location == RESOURCE_IN_WIM && lte->wim == _wim) {
+ copy_resource_entry(<e->output_resource_entry,
+ <e->resource_entry);
+ }
+ return 0;
+}
+
+/* Given a WIM that we are going to overwrite in place with zero or more
+ * additional streams added, construct a list the list of new unique streams
+ * ('struct wim_lookup_table_entry's) that must be written, plus any unhashed
+ * streams that need to be added but may be identical to other hashed or
+ * unhashed streams. These unhashed streams are checksummed while the streams
+ * are being written. To aid this process, the member @unique_size is set to 1
+ * on streams that have a unique size and therefore must be written.
+ *
+ * The out_refcnt member of each 'struct wim_lookup_table_entry' is set to
+ * indicate the number of times the stream is referenced in only the streams
+ * that are being written; this may still be adjusted later when unhashed
+ * streams are being resolved.
+ */
+static int
+prepare_streams_for_overwrite(WIMStruct *wim, off_t end_offset,
+ struct list_head *stream_list)
+{
+ int ret;
+ struct lte_overwrite_prepare_args args;
+
+ args.wim = wim;
+ args.end_offset = end_offset;
+ ret = init_stream_size_table(&args.stream_size_tab,
+ wim->lookup_table->capacity);
+ if (ret)
+ return ret;
+
+ INIT_LIST_HEAD(&args.stream_list);
+ for (int i = 0; i < wim->hdr.image_count; i++) {
+ struct wim_image_metadata *imd;
+ struct wim_lookup_table_entry *lte;
+
+ imd = wim->image_metadata[i];
+ image_for_each_unhashed_stream(lte, imd) {
+ ret = lte_overwrite_prepare(lte, &args);
+ if (ret)
+ goto out_destroy_stream_size_table;
+ }
+ }
+ ret = for_lookup_table_entry(wim->lookup_table,
+ lte_overwrite_prepare, &args);
+ if (ret)
+ goto out_destroy_stream_size_table;
+
+ for (int i = 0; i < wim->hdr.image_count; i++)
+ lte_set_output_res_entry(wim->image_metadata[i]->metadata_lte,
+ wim);
+ for_lookup_table_entry(wim->lookup_table, lte_set_output_res_entry, wim);
+ list_transfer(&args.stream_list, stream_list);
+out_destroy_stream_size_table:
+ destroy_stream_size_table(&args.stream_size_tab);
+ return ret;
+}
+
+
+struct find_streams_ctx {
+ struct list_head stream_list;
+ struct stream_size_table stream_size_tab;
+};
+
+static void
+inode_find_streams_to_write(struct wim_inode *inode,
+ struct wim_lookup_table *table,
+ struct list_head *stream_list,
+ struct stream_size_table *tab)
+{
+ struct wim_lookup_table_entry *lte;
+ for (unsigned i = 0; i <= inode->i_num_ads; i++) {
+ lte = inode_stream_lte(inode, i, table);
+ if (lte) {
+ if (lte->out_refcnt == 0) {
+ if (lte->unhashed)
+ stream_size_table_insert(lte, tab);
+ list_add_tail(<e->write_streams_list, stream_list);
+ }
+ lte->out_refcnt += inode->i_nlink;
+ }
+ }
+}
+
+static int
+image_find_streams_to_write(WIMStruct *w)
+{
+ struct find_streams_ctx *ctx;
+ struct wim_image_metadata *imd;
+ struct wim_inode *inode;
+ struct wim_lookup_table_entry *lte;
+
+ ctx = w->private;
+ imd = wim_get_current_image_metadata(w);
+
+ image_for_each_unhashed_stream(lte, imd)
+ lte->out_refcnt = 0;
+
+ /* Go through this image's inodes to find any streams that have not been
+ * found yet. */
+ image_for_each_inode(inode, imd) {
+ inode_find_streams_to_write(inode, w->lookup_table,
+ &ctx->stream_list,
+ &ctx->stream_size_tab);
+ }
+ return 0;
+}
+
+/* Given a WIM that from which one or all of the images is being written, build
+ * the list of unique streams ('struct wim_lookup_table_entry's) that must be
+ * written, plus any unhashed streams that need to be written but may be
+ * identical to other hashed or unhashed streams being written. These unhashed
+ * streams are checksummed while the streams are being written. To aid this
+ * process, the member @unique_size is set to 1 on streams that have a unique
+ * size and therefore must be written.
+ *
+ * The out_refcnt member of each 'struct wim_lookup_table_entry' is set to
+ * indicate the number of times the stream is referenced in only the streams
+ * that are being written; this may still be adjusted later when unhashed
+ * streams are being resolved.
+ */
+static int
+prepare_stream_list(WIMStruct *wim, int image, struct list_head *stream_list)
+{
+ int ret;
+ struct find_streams_ctx ctx;
+
+ for_lookup_table_entry(wim->lookup_table, lte_zero_out_refcnt, NULL);
+ ret = init_stream_size_table(&ctx.stream_size_tab,
+ wim->lookup_table->capacity);
+ if (ret)
+ return ret;
+ for_lookup_table_entry(wim->lookup_table, stream_size_table_insert,
+ &ctx.stream_size_tab);
+ INIT_LIST_HEAD(&ctx.stream_list);
+ wim->private = &ctx;
+ ret = for_image(wim, image, image_find_streams_to_write);
+ destroy_stream_size_table(&ctx.stream_size_tab);
+ if (ret == 0)
+ list_transfer(&ctx.stream_list, stream_list);
+ return ret;
+}
+
+/* Writes the streams for the specified @image in @wim to @wim->out_fp.
+ */
+static int
+write_wim_streams(WIMStruct *wim, int image, int write_flags,
+ unsigned num_threads,
+ wimlib_progress_func_t progress_func)
+{
+ int ret;
+ struct list_head stream_list;
+
+ ret = prepare_stream_list(wim, image, &stream_list);
+ if (ret)
+ return ret;
+ return write_stream_list(&stream_list,
+ wim->lookup_table,
+ wim->out_fp,
+ wimlib_get_compression_type(wim),
+ write_flags,
+ num_threads,
+ progress_func);
+}
+
+/*
+ * Finish writing a WIM file: write the lookup table, xml data, and integrity
+ * table (optional), then overwrite the WIM header.
+ *
+ * write_flags is a bitwise OR of the following:
+ *
+ * (public) WIMLIB_WRITE_FLAG_CHECK_INTEGRITY:
+ * Include an integrity table.
+ *
+ * (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;
+
+ /* @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));
+
+ /* Set image count and boot index correctly for single image writes */
+ if (image != WIMLIB_ALL_IMAGES) {
+ hdr.image_count = 1;
+ if (hdr.boot_idx == image)
+ hdr.boot_idx = 1;
+ else
+ hdr.boot_idx = 0;
+ }
+
+ /* 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) {
+ zero_resource_entry(&hdr.boot_metadata_res_entry);
+ } else {
+ copy_resource_entry(&hdr.boot_metadata_res_entry,
+ &w->image_metadata[ hdr.boot_idx- 1
+ ]->metadata_lte->output_resource_entry);
+ }
+
+ if (!(write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE)) {
+ ret = write_lookup_table(w, image, &hdr.lookup_table_res_entry);
+ if (ret)
+ goto out_close_wim;
+ }
+
+ ret = write_xml_data(w->wim_info, image, out,
+ (write_flags & WIMLIB_WRITE_FLAG_NO_LOOKUP_TABLE) ?
+ wim_info_get_total_bytes(w->wim_info) : 0,
+ &hdr.xml_res_entry);
+ if (ret)
+ goto out_close_wim;
+
+ if (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) {
+ if (write_flags & WIMLIB_WRITE_FLAG_CHECKPOINT_AFTER_XML) {
+ struct wim_header checkpoint_hdr;
+ memcpy(&checkpoint_hdr, &hdr, sizeof(struct wim_header));
+ zero_resource_entry(&checkpoint_hdr.integrity);
+ if (fseeko(out, 0, SEEK_SET)) {
+ ERROR_WITH_ERRNO("Failed to seek to beginning "
+ "of WIM being written");
+ ret = WIMLIB_ERR_WRITE;
+ goto out_close_wim;
+ }
+ ret = write_header(&checkpoint_hdr, out);
+ if (ret)
+ goto out_close_wim;
+
+ if (fflush(out) != 0) {
+ ERROR_WITH_ERRNO("Can't write data to WIM");
+ ret = WIMLIB_ERR_WRITE;
+ goto out_close_wim;
+ }
+
+ 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_close_wim;
+ }
+ }
+
+ off_t old_lookup_table_end;
+ off_t new_lookup_table_end;
+ if (write_flags & WIMLIB_WRITE_FLAG_REUSE_INTEGRITY_TABLE) {
+ old_lookup_table_end = w->hdr.lookup_table_res_entry.offset +
+ w->hdr.lookup_table_res_entry.size;
+ } else {
+ old_lookup_table_end = 0;
+ }
+ new_lookup_table_end = hdr.lookup_table_res_entry.offset +
+ hdr.lookup_table_res_entry.size;
+
+ ret = write_integrity_table(out,
+ &hdr.integrity,
+ new_lookup_table_end,
+ old_lookup_table_end,
+ progress_func);
+ if (ret)
+ goto out_close_wim;
+ } else {
+ zero_resource_entry(&hdr.integrity);
+ }
+
+ 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_close_wim;
+ }
+
+ ret = write_header(&hdr, out);
+ if (ret)
+ goto out_close_wim;
+
+ 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_close_wim:
+ if (fclose(out) != 0) {
+ ERROR_WITH_ERRNO("Failed to close the output WIM file");
+ if (ret == 0)
+ ret = WIMLIB_ERR_WRITE;
+ }
+ w->out_fp = NULL;
+ return ret;
+}
+
+#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("`%"TS"' is already being modified or has been "
+ "mounted read-write\n"
+ " by another process!", w->filename);
+ ret = WIMLIB_ERR_ALREADY_LOCKED;
+ } else {
+ WARNING_WITH_ERRNO("Failed to lock `%"TS"'",
+ w->filename);
+ ret = 0;
+ }
+ } else {
+ w->wim_locked = 1;
+ }
+ }
+ return ret;
+}
+#endif
+
+static int
+open_wim_writable(WIMStruct *w, const tchar *path,
+ bool trunc, bool also_readable)
+{
+ const tchar *mode;
+ if (trunc)
+ if (also_readable)
+ mode = T("w+b");
+ else
+ mode = T("wb");
+ else
+ mode = T("r+b");
+
+ wimlib_assert(w->out_fp == NULL);
+ w->out_fp = tfopen(path, mode);
+ if (w->out_fp) {
+ return 0;
+ } else {
+ ERROR_WITH_ERRNO("Failed to open `%"TS"' 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 tchar *path, int write_flags)
+{
+ int ret;
+ ret = open_wim_writable(w, path, true,
+ (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) != 0);
+ if (ret)
+ return ret;
+ /* Write dummy header. It will be overwritten later. */
+ return write_header(&w->hdr, w->out_fp);
+}
+
+/* Writes a stand-alone WIM to a file. */
+WIMLIBAPI int
+wimlib_write(WIMStruct *w, const tchar *path,
+ int image, int write_flags, unsigned num_threads,
+ wimlib_progress_func_t progress_func)
+{
+ int ret;
+
+ if (!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 (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)
+ goto out_close_wim;
+
+ ret = write_wim_streams(w, image, write_flags, num_threads,
+ progress_func);
+ if (ret)
+ goto out_close_wim;
+
+ if (progress_func)
+ progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_BEGIN, NULL);
+
+ ret = for_image(w, image, write_metadata_resource);
+ if (ret)
+ goto out_close_wim;
+
+ if (progress_func)
+ progress_func(WIMLIB_PROGRESS_MSG_WRITE_METADATA_END, NULL);
+
+ ret = finish_write(w, image, write_flags, progress_func);
+ /* finish_write() closed the WIM for us */
+ goto out;
+out_close_wim:
+ close_wim_writable(w);
+out:
+ DEBUG("wimlib_write(path=%"TS") = %d", path, ret);
+ return ret;
+}
+
+static bool
+any_images_modified(WIMStruct *w)
+{
+ for (int i = 0; i < w->hdr.image_count; i++)
+ if (w->image_metadata[i]->modified)
+ return true;
+ return false;
+}
+
+/*
+ * 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;
+
+ DEBUG("Overwriting `%"TS"' in-place", w->filename);
+
+ /* Make sure that the integrity table (if present) is after the XML
+ * data, and that there are no stream resources, metadata resources, or
+ * lookup tables after the XML data. Otherwise, these data would be
+ * overwritten. */
+ 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
+ old_wim_end = w->hdr.xml_res_entry.offset + w->hdr.xml_res_entry.size;
+
+ 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. */
+ DEBUG("Skipping writing lookup table "
+ "(no images modified or deleted)");
+ 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;
+ }
+ ret = prepare_streams_for_overwrite(w, old_wim_end, &stream_list);
+ if (ret)
+ return ret;
+
+ ret = open_wim_writable(w, w->filename, false,
+ (write_flags & WIMLIB_WRITE_FLAG_CHECK_INTEGRITY) != 0);
+ if (ret)
+ return ret;
+
+ ret = lock_wim(w, w->out_fp);
+ if (ret) {
+ fclose(w->out_fp);
+ w->out_fp = NULL;
+ return ret;
+ }
+
+ 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;
+ }
+
+ DEBUG("Writing newly added streams (offset = %"PRIu64")",
+ old_wim_end);
+ ret = write_stream_list(&stream_list,
+ w->lookup_table,
+ w->out_fp,
+ wimlib_get_compression_type(w),
+ write_flags,
+ num_threads,
+ progress_func);
+ if (ret)
+ goto out_ftruncate;
+
+ for (int i = 0; i < w->hdr.image_count; i++) {
+ if (w->image_metadata[i]->modified) {
+ select_wim_image(w, i + 1);
+ ret = write_metadata_resource(w);
+ if (ret)
+ goto out_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 `%"TS"' to its original size (%"PRIu64" bytes)",
+ w->filename, old_wim_end);
+ /* Return value of truncate() is ignored because this is already
+ * an error path. */
+ (void)ttruncate(w->filename, old_wim_end);
+ }
+ w->wim_locked = 0;
+ return ret;
+}
+
+static int
+overwrite_wim_via_tmpfile(WIMStruct *w, int write_flags,
+ unsigned num_threads,
+ wimlib_progress_func_t progress_func)
+{
+ size_t wim_name_len;
+ int ret;
+
+ DEBUG("Overwriting `%"TS"' via a temporary file", w->filename);
+
+ /* Write the WIM to a temporary file in the same directory as the
+ * original WIM. */
+ wim_name_len = tstrlen(w->filename);
+ tchar tmpfile[wim_name_len + 10];
+ tmemcpy(tmpfile, w->filename, wim_name_len);
+ randomize_char_array_with_alnum(tmpfile + wim_name_len, 9);
+ tmpfile[wim_name_len + 9] = T('\0');
+
+ ret = wimlib_write(w, tmpfile, WIMLIB_ALL_IMAGES,
+ write_flags | WIMLIB_WRITE_FLAG_FSYNC,
+ num_threads, progress_func);
+ if (ret) {
+ ERROR("Failed to write the WIM file `%"TS"'", tmpfile);
+ goto out_unlink;
+ }
+
+ DEBUG("Renaming `%"TS"' to `%"TS"'", tmpfile, w->filename);
+
+#ifdef __WIN32__
+ /* Windows won't let you delete open files unless FILE_SHARE_DELETE was
+ * specified to CreateFile(). The WIM was opened with fopen(), which
+ * didn't provided this flag to CreateFile, so the handle must be closed
+ * before executing the rename(). */
+ if (w->fp != NULL) {
+ fclose(w->fp);
+ w->fp = NULL;
+ }
+#endif
+
+ /* Rename the new file to the old file .*/
+ if (trename(tmpfile, w->filename) != 0) {
+ ERROR_WITH_ERRNO("Failed to rename `%"TS"' to `%"TS"'",
+ tmpfile, w->filename);
+ ret = WIMLIB_ERR_RENAME;
+ goto out_unlink;
+ }
+
+ if (progress_func) {
+ union wimlib_progress_info progress;
+ progress.rename.from = tmpfile;
+ progress.rename.to = w->filename;
+ progress_func(WIMLIB_PROGRESS_MSG_RENAME, &progress);
+ }
+
+ /* 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 = tfopen(w->filename, T("rb"));
+ if (w->fp == NULL) {
+ ret = WIMLIB_ERR_REOPEN;
+ WARNING_WITH_ERRNO("Failed to re-open `%"TS"' read-only",
+ w->filename);
+ FREE(w->filename);
+ w->filename = NULL;
+ }
+ goto out;
+out_unlink:
+ /* Remove temporary file. */
+ if (tunlink(tmpfile) != 0)
+ WARNING_WITH_ERRNO("Failed to remove `%"TS"'", tmpfile);
+out:
+ return ret;
+}
+
+/*
+ * Writes a WIM file to the original file that it was read from, overwriting it.
+ */
+WIMLIBAPI int
+wimlib_overwrite(WIMStruct *w, int write_flags,
+ unsigned num_threads,
+ wimlib_progress_func_t progress_func)
+{
+ 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);
+}