]> wimlib.net Git - wimlib/blobdiff - src/resource.c
Cache compression format in 'struct wim_resource_spec'
[wimlib] / src / resource.c
index 192ffb2e988470252f92fda501a226664ee3f04c..116873ffc16b68d9be4c590631a4f2167964722a 100644 (file)
@@ -175,37 +175,21 @@ read_compressed_wim_resource(const struct wim_resource_spec * const rspec,
 
        /* 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;
-       int ctype;
+       int ctype = rspec->compression_type;
+       u32 chunk_size = rspec->chunk_size;
        if (alt_chunk_table) {
                /* Alternate chunk table format.  Its header specifies the chunk
-                * size and compression format.  */
-               struct alt_chunk_table_header_disk hdr;
-
-               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);
-               ctype = le32_to_cpu(hdr.compression_format);
-
-               /* Format numbers must be the same as in WIMGAPI to be
-                * compatible.  */
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_NONE != 0);
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZX != 1);
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_XPRESS != 2);
-               BUILD_BUG_ON(WIMLIB_COMPRESSION_TYPE_LZMS != 3);
-       } else {
-               /* "Normal" format: the maximum uncompressed chunk size and the
-                * compression format default to those of the WIM itself.  */
-               chunk_size = rspec->wim->chunk_size;
-               ctype = rspec->wim->compression_type;
+                * size and compression format.  Note: it could be read here;
+                * however, the relevant data was already loaded into @rspec by
+                * read_wim_lookup_table().  */
+               cur_read_offset += sizeof(struct alt_chunk_table_header_disk);
        }
+
        if (!is_power_of_2(chunk_size)) {
                ERROR("Invalid compressed resource: "
-                     "expected power-of-2 chunk size (got %u)", chunk_size);
+                     "expected power-of-2 chunk size (got %"PRIu32")",
+                     chunk_size);
                ret = WIMLIB_ERR_INVALID_CHUNK_SIZE;
                goto out_free_memory;
        }
@@ -253,11 +237,9 @@ read_compressed_wim_resource(const struct wim_resource_spec * const rspec,
        const u64 num_chunk_entries = (alt_chunk_table ? num_chunks : num_chunks - 1);
 
        /* 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;
+        * uncompressed size.  */
+       const u64 chunk_entry_size = get_chunk_entry_size(rspec->uncompressed_size,
+                                                         alt_chunk_table);
 
        /* Calculate the size of the chunk table in bytes.  */
        const u64 chunk_table_size = num_chunk_entries * chunk_entry_size;
@@ -1098,6 +1080,82 @@ read_full_stream_with_sha1(struct wim_lookup_table_entry *lte,
        return read_full_stream_with_cbs(lte, &hasher_cbs);
 }
 
+static int
+read_packed_streams(struct wim_lookup_table_entry *first_stream,
+                   struct wim_lookup_table_entry *last_stream,
+                   u64 stream_count,
+                   size_t list_head_offset,
+                   const struct read_stream_list_callbacks *sink_cbs)
+{
+       struct data_range *ranges;
+       bool ranges_malloced;
+       struct wim_lookup_table_entry *cur_stream;
+       size_t i;
+       int ret;
+       u64 ranges_alloc_size;
+
+       DEBUG("Reading %"PRIu64" streams combined in same WIM resource",
+             stream_count);
+
+       /* Setup data ranges array (one range per stream to read); this way
+        * read_compressed_wim_resource() does not need to be aware of streams.
+        */
+
+       ranges_alloc_size = stream_count * sizeof(ranges[0]);
+
+       if (unlikely((size_t)ranges_alloc_size != ranges_alloc_size)) {
+               ERROR("Too many streams in one resource!");
+               return WIMLIB_ERR_NOMEM;
+       }
+       if (likely(ranges_alloc_size <= STACK_MAX)) {
+               ranges = alloca(ranges_alloc_size);
+               ranges_malloced = false;
+       } else {
+               ranges = MALLOC(ranges_alloc_size);
+               if (ranges == NULL) {
+                       ERROR("Too many streams in one resource!");
+                       return WIMLIB_ERR_NOMEM;
+               }
+               ranges_malloced = true;
+       }
+
+       for (i = 0, cur_stream = first_stream;
+            i < stream_count;
+            i++, cur_stream = next_stream(cur_stream, list_head_offset))
+       {
+               ranges[i].offset = cur_stream->offset_in_res;
+               ranges[i].size = cur_stream->size;
+       }
+
+       struct streamifier_context streamifier_ctx = {
+               .cbs                    = *sink_cbs,
+               .cur_stream             = first_stream,
+               .next_stream            = next_stream(first_stream, list_head_offset),
+               .cur_stream_offset      = 0,
+               .final_stream           = last_stream,
+               .list_head_offset       = list_head_offset,
+       };
+
+       ret = read_compressed_wim_resource(first_stream->rspec,
+                                          ranges,
+                                          stream_count,
+                                          streamifier_cb,
+                                          &streamifier_ctx);
+
+       if (ranges_malloced)
+               FREE(ranges);
+
+       if (ret) {
+               if (streamifier_ctx.cur_stream_offset != 0) {
+                       ret = (*streamifier_ctx.cbs.end_stream)
+                               (streamifier_ctx.cur_stream,
+                                ret,
+                                streamifier_ctx.cbs.end_stream_ctx);
+               }
+       }
+       return ret;
+}
+
 /*
  * 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
@@ -1186,7 +1244,7 @@ read_stream_list(struct list_head *stream_list,
 
                        struct wim_lookup_table_entry *lte_next, *lte_last;
                        struct list_head *next2;
-                       size_t stream_count;
+                       u64 stream_count;
 
                        /* The next stream is a proper sub-sequence of a WIM
                         * resource.  See if there are other streams in the same
@@ -1215,53 +1273,13 @@ read_stream_list(struct list_head *stream_list,
                                 * 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.  */
-
-                               DEBUG("Reading %zu streams combined in same "
-                                     "WIM resource", stream_count);
-
                                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 streamifier_context streamifier_ctx = {
-                                       .cbs                    = *sink_cbs,
-                                       .cur_stream             = lte,
-                                       .next_stream            = next_stream(lte, list_head_offset),
-                                       .cur_stream_offset      = 0,
-                                       .final_stream           = lte_last,
-                                       .list_head_offset       = list_head_offset,
-                               };
-
-                               ret = read_compressed_wim_resource(lte->rspec,
-                                                                  ranges,
-                                                                  stream_count,
-                                                                  streamifier_cb,
-                                                                  &streamifier_ctx);
-
-                               if (ret) {
-                                       if (streamifier_ctx.cur_stream_offset != 0) {
-                                               ret = (*streamifier_ctx.cbs.end_stream)
-                                                       (streamifier_ctx.cur_stream,
-                                                        ret,
-                                                        streamifier_ctx.cbs.end_stream_ctx);
-                                       }
+                               ret = read_packed_streams(lte, lte_last,
+                                                         stream_count,
+                                                         list_head_offset,
+                                                         sink_cbs);
+                               if (ret)
                                        return ret;
-                               }
                                continue;
                        }
                }
@@ -1323,6 +1341,15 @@ extract_stream_to_fd(struct wim_lookup_table_entry *lte,
        return extract_stream(lte, size, extract_chunk_to_fd, fd);
 }
 
+/* Extract the full uncompressed contents of the specified stream to the
+ * specified file descriptor.  */
+int
+extract_full_stream_to_fd(struct wim_lookup_table_entry *lte,
+                         struct filedes *fd)
+{
+       return extract_stream_to_fd(lte, fd, lte->size);
+}
+
 /* Calculate the SHA1 message digest of a stream and store it in @lte->hash.  */
 int
 sha1_stream(struct wim_lookup_table_entry *lte)
@@ -1334,7 +1361,10 @@ sha1_stream(struct wim_lookup_table_entry *lte)
 }
 
 /* Convert a short WIM resource header to a stand-alone WIM resource
- * specification.  */
+ * specification.
+ *
+ * Note: for packed resources some fields still need to be overridden.
+ */
 void
 wim_res_hdr_to_spec(const struct wim_reshdr *reshdr, WIMStruct *wim,
                    struct wim_resource_spec *rspec)
@@ -1346,6 +1376,13 @@ wim_res_hdr_to_spec(const struct wim_reshdr *reshdr, WIMStruct *wim,
        INIT_LIST_HEAD(&rspec->stream_list);
        rspec->flags = reshdr->flags;
        rspec->is_pipable = wim_is_pipable(wim);
+       if (rspec->flags & WIM_RESHDR_FLAG_COMPRESSED) {
+               rspec->compression_type = wim->compression_type;
+               rspec->chunk_size = wim->chunk_size;
+       } else {
+               rspec->compression_type = WIMLIB_COMPRESSION_TYPE_NONE;
+               rspec->chunk_size = 0;
+       }
 }
 
 /* Convert a stand-alone resource specification to a WIM resource header.  */