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-rw-r--r--applypatch/imgdiff.cpp189
-rw-r--r--applypatch/include/applypatch/imgdiff_image.h6
-rw-r--r--tests/component/imgdiff_test.cpp48
3 files changed, 174 insertions, 69 deletions
diff --git a/applypatch/imgdiff.cpp b/applypatch/imgdiff.cpp
index 2eb618fbf..c887a854d 100644
--- a/applypatch/imgdiff.cpp
+++ b/applypatch/imgdiff.cpp
@@ -15,53 +15,44 @@
*/
/*
- * This program constructs binary patches for images -- such as boot.img
- * and recovery.img -- that consist primarily of large chunks of gzipped
- * data interspersed with uncompressed data. Doing a naive bsdiff of
- * these files is not useful because small changes in the data lead to
- * large changes in the compressed bitstream; bsdiff patches of gzipped
- * data are typically as large as the data itself.
+ * This program constructs binary patches for images -- such as boot.img and recovery.img -- that
+ * consist primarily of large chunks of gzipped data interspersed with uncompressed data. Doing a
+ * naive bsdiff of these files is not useful because small changes in the data lead to large
+ * changes in the compressed bitstream; bsdiff patches of gzipped data are typically as large as
+ * the data itself.
*
- * To patch these usefully, we break the source and target images up into
- * chunks of two types: "normal" and "gzip". Normal chunks are simply
- * patched using a plain bsdiff. Gzip chunks are first expanded, then a
- * bsdiff is applied to the uncompressed data, then the patched data is
- * gzipped using the same encoder parameters. Patched chunks are
- * concatenated together to create the output file; the output image
- * should be *exactly* the same series of bytes as the target image used
- * originally to generate the patch.
+ * To patch these usefully, we break the source and target images up into chunks of two types:
+ * "normal" and "gzip". Normal chunks are simply patched using a plain bsdiff. Gzip chunks are
+ * first expanded, then a bsdiff is applied to the uncompressed data, then the patched data is
+ * gzipped using the same encoder parameters. Patched chunks are concatenated together to create
+ * the output file; the output image should be *exactly* the same series of bytes as the target
+ * image used originally to generate the patch.
*
- * To work well with this tool, the gzipped sections of the target
- * image must have been generated using the same deflate encoder that
- * is available in applypatch, namely, the one in the zlib library.
- * In practice this means that images should be compressed using the
- * "minigzip" tool included in the zlib distribution, not the GNU gzip
- * program.
+ * To work well with this tool, the gzipped sections of the target image must have been generated
+ * using the same deflate encoder that is available in applypatch, namely, the one in the zlib
+ * library. In practice this means that images should be compressed using the "minigzip" tool
+ * included in the zlib distribution, not the GNU gzip program.
*
- * An "imgdiff" patch consists of a header describing the chunk structure
- * of the file and any encoding parameters needed for the gzipped
- * chunks, followed by N bsdiff patches, one per chunk.
+ * An "imgdiff" patch consists of a header describing the chunk structure of the file and any
+ * encoding parameters needed for the gzipped chunks, followed by N bsdiff patches, one per chunk.
*
- * For a diff to be generated, the source and target images must have the
- * same "chunk" structure: that is, the same number of gzipped and normal
- * chunks in the same order. Android boot and recovery images currently
- * consist of five chunks: a small normal header, a gzipped kernel, a
- * small normal section, a gzipped ramdisk, and finally a small normal
- * footer.
+ * For a diff to be generated, the source and target must be in well-formed zip archive format;
+ * or they are image files with the same "chunk" structure: that is, the same number of gzipped and
+ * normal chunks in the same order. Android boot and recovery images currently consist of five
+ * chunks: a small normal header, a gzipped kernel, a small normal section, a gzipped ramdisk, and
+ * finally a small normal footer.
*
- * Caveats: we locate gzipped sections within the source and target
- * images by searching for the byte sequence 1f8b0800: 1f8b is the gzip
- * magic number; 08 specifies the "deflate" encoding [the only encoding
- * supported by the gzip standard]; and 00 is the flags byte. We do not
- * currently support any extra header fields (which would be indicated by
- * a nonzero flags byte). We also don't handle the case when that byte
- * sequence appears spuriously in the file. (Note that it would have to
- * occur spuriously within a normal chunk to be a problem.)
+ * Caveats: we locate gzipped sections within the source and target images by searching for the
+ * byte sequence 1f8b0800: 1f8b is the gzip magic number; 08 specifies the "deflate" encoding
+ * [the only encoding supported by the gzip standard]; and 00 is the flags byte. We do not
+ * currently support any extra header fields (which would be indicated by a nonzero flags byte).
+ * We also don't handle the case when that byte sequence appears spuriously in the file. (Note
+ * that it would have to occur spuriously within a normal chunk to be a problem.)
*
*
* The imgdiff patch header looks like this:
*
- * "IMGDIFF1" (8) [magic number and version]
+ * "IMGDIFF2" (8) [magic number and version]
* chunk count (4)
* for each chunk:
* chunk type (4) [CHUNK_{NORMAL, GZIP, DEFLATE, RAW}]
@@ -98,27 +89,55 @@
* target len (4)
* data (target len)
*
- * All integers are little-endian. "source start" and "source len"
- * specify the section of the input image that comprises this chunk,
- * including the gzip header and footer for gzip chunks. "source
- * expanded len" is the size of the uncompressed source data. "target
- * expected len" is the size of the uncompressed data after applying
- * the bsdiff patch. The next five parameters specify the zlib
- * parameters to be used when compressing the patched data, and the
- * next three specify the header and footer to be wrapped around the
- * compressed data to create the output chunk (so that header contents
- * like the timestamp are recreated exactly).
+ * All integers are little-endian. "source start" and "source len" specify the section of the
+ * input image that comprises this chunk, including the gzip header and footer for gzip chunks.
+ * "source expanded len" is the size of the uncompressed source data. "target expected len" is the
+ * size of the uncompressed data after applying the bsdiff patch. The next five parameters
+ * specify the zlib parameters to be used when compressing the patched data, and the next three
+ * specify the header and footer to be wrapped around the compressed data to create the output
+ * chunk (so that header contents like the timestamp are recreated exactly).
*
- * After the header there are 'chunk count' bsdiff patches; the offset
- * of each from the beginning of the file is specified in the header.
+ * After the header there are 'chunk count' bsdiff patches; the offset of each from the beginning
+ * of the file is specified in the header.
*
- * This tool can take an optional file of "bonus data". This is an
- * extra file of data that is appended to chunk #1 after it is
- * compressed (it must be a CHUNK_DEFLATE chunk). The same file must
- * be available (and passed to applypatch with -b) when applying the
- * patch. This is used to reduce the size of recovery-from-boot
- * patches by combining the boot image with recovery ramdisk
+ * This tool can take an optional file of "bonus data". This is an extra file of data that is
+ * appended to chunk #1 after it is compressed (it must be a CHUNK_DEFLATE chunk). The same file
+ * must be available (and passed to applypatch with -b) when applying the patch. This is used to
+ * reduce the size of recovery-from-boot patches by combining the boot image with recovery ramdisk
* information that is stored on the system partition.
+ *
+ * When generating the patch between two zip files, this tool has an option "--block-limit" to
+ * split the large source/target files into several pair of pieces, with each piece has at most
+ * *limit* blocks. When this option is used, we also need to output the split info into the file
+ * path specified by "--split-info".
+ *
+ * Format of split info file:
+ * 2 [version of imgdiff]
+ * n [count of split pieces]
+ * <patch_size>, <tgt_size>, <src_range> [size and ranges for split piece#1]
+ * ...
+ * <patch_size>, <tgt_size>, <src_range> [size and ranges for split piece#n]
+ *
+ * To split a pair of large zip files, we walk through the chunks in target zip and search by its
+ * entry_name in the source zip. If the entry_name is non-empty and a matching entry in source
+ * is found, we'll add the source entry to the current split source image; otherwise we'll skip
+ * this chunk and later do bsdiff between all the skipped trunks and the whole split source image.
+ * We move on to the next pair of pieces if the size of the split source image reaches the block
+ * limit.
+ *
+ * After the split, the target pieces are continuous and block aligned, while the source pieces
+ * are mutually exclusive. Some of the source blocks may not be used if there's no matching
+ * entry_name in the target; as a result, they won't be included in any of these split source
+ * images. Then we will generate patches accordingly between each split image pairs; in particular,
+ * the unmatched trunks in the split target will diff against the entire split source image.
+ *
+ * For example:
+ * Input: [src_image, tgt_image]
+ * Split: [src-0, tgt-0; src-1, tgt-1, src-2, tgt-2]
+ * Diff: [ patch-0; patch-1; patch-2]
+ *
+ * Patch: [(src-0, patch-0) = tgt-0; (src-1, patch-1) = tgt-1; (src-2, patch-2) = tgt-2]
+ * Concatenate: [tgt-0 + tgt-1 + tgt-2 = tgt_image]
*/
#include "applypatch/imgdiff.h"
@@ -151,6 +170,11 @@
using android::base::get_unaligned;
+static constexpr size_t VERSION = 2;
+
+// We assume the header "IMGDIFF#" is 8 bytes.
+static_assert(VERSION <= 9, "VERSION occupies more than one byte.");
+
static constexpr size_t BLOCK_SIZE = 4096;
static constexpr size_t BUFFER_SIZE = 0x8000;
@@ -224,6 +248,7 @@ static const struct option OPTIONS[] = {
{ "bonus-file", required_argument, nullptr, 'b' },
{ "block-limit", required_argument, nullptr, 0 },
{ "debug-dir", required_argument, nullptr, 0 },
+ { "split-info", required_argument, nullptr, 0 },
{ nullptr, 0, nullptr, 0 },
};
@@ -497,6 +522,13 @@ size_t PatchChunk::WriteHeaderToFd(int fd, size_t offset) const {
}
}
+size_t PatchChunk::PatchSize() const {
+ if (type_ == CHUNK_RAW) {
+ return GetHeaderSize();
+ }
+ return GetHeaderSize() + data_.size();
+}
+
// Write the contents of |patch_chunks| to |patch_fd|.
bool PatchChunk::WritePatchDataToFd(const std::vector<PatchChunk>& patch_chunks, int patch_fd) {
// Figure out how big the imgdiff file header is going to be, so that we can correctly compute
@@ -509,8 +541,8 @@ bool PatchChunk::WritePatchDataToFd(const std::vector<PatchChunk>& patch_chunks,
size_t offset = total_header_size;
// Write out the headers.
- if (!android::base::WriteStringToFd("IMGDIFF2", patch_fd)) {
- printf("failed to write \"IMGDIFF2\": %s\n", strerror(errno));
+ if (!android::base::WriteStringToFd("IMGDIFF" + std::to_string(VERSION), patch_fd)) {
+ printf("failed to write \"IMGDIFF%zu\": %s\n", VERSION, strerror(errno));
return false;
}
@@ -1107,7 +1139,9 @@ bool ZipModeImage::GeneratePatches(const ZipModeImage& tgt_image, const ZipModeI
bool ZipModeImage::GeneratePatches(const std::vector<ZipModeImage>& split_tgt_images,
const std::vector<ZipModeImage>& split_src_images,
const std::vector<SortedRangeSet>& split_src_ranges,
- const std::string& patch_name, const std::string& debug_dir) {
+ const std::string& patch_name,
+ const std::string& split_info_file,
+ const std::string& debug_dir) {
printf("Construct patches for %zu split images...\n", split_tgt_images.size());
android::base::unique_fd patch_fd(
@@ -1117,6 +1151,7 @@ bool ZipModeImage::GeneratePatches(const std::vector<ZipModeImage>& split_tgt_im
return false;
}
+ std::vector<std::string> split_info_list;
for (size_t i = 0; i < split_tgt_images.size(); i++) {
std::vector<PatchChunk> patch_chunks;
if (!ZipModeImage::GeneratePatchesInternal(split_tgt_images[i], split_src_images[i],
@@ -1125,14 +1160,23 @@ bool ZipModeImage::GeneratePatches(const std::vector<ZipModeImage>& split_tgt_im
return false;
}
+ size_t total_patch_size = 12;
for (auto& p : patch_chunks) {
p.UpdateSourceOffset(split_src_ranges[i]);
+ total_patch_size += p.PatchSize();
}
if (!PatchChunk::WritePatchDataToFd(patch_chunks, patch_fd)) {
return false;
}
+ size_t split_tgt_size = split_tgt_images[i].chunks_.back().GetStartOffset() +
+ split_tgt_images[i].chunks_.back().GetRawDataLength() -
+ split_tgt_images[i].chunks_.front().GetStartOffset();
+ std::string split_info = android::base::StringPrintf(
+ "%zu %zu %s", total_patch_size, split_tgt_size, split_src_ranges[i].ToString().c_str());
+ split_info_list.push_back(split_info);
+
// Write the split source & patch into the debug directory.
if (!debug_dir.empty()) {
std::string src_name = android::base::StringPrintf("%s/src-%zu", debug_dir.c_str(), i);
@@ -1161,6 +1205,21 @@ bool ZipModeImage::GeneratePatches(const std::vector<ZipModeImage>& split_tgt_im
}
}
}
+
+ // Store the split in the following format:
+ // Line 0: imgdiff version#
+ // Line 1: number of pieces
+ // Line 2: patch_size_1 tgt_size_1 src_range_1
+ // ...
+ // Line n+1: patch_size_n tgt_size_n src_range_n
+ std::string split_info_string = android::base::StringPrintf(
+ "%zu\n%zu\n", VERSION, split_info_list.size()) + android::base::Join(split_info_list, '\n');
+ if (!android::base::WriteStringToFile(split_info_string, split_info_file)) {
+ printf("failed to write split info to \"%s\": %s\n", split_info_file.c_str(),
+ strerror(errno));
+ return false;
+ }
+
return true;
}
@@ -1396,6 +1455,7 @@ int imgdiff(int argc, const char** argv) {
bool zip_mode = false;
std::vector<uint8_t> bonus_data;
size_t blocks_limit = 0;
+ std::string split_info_file;
std::string debug_dir;
int opt;
@@ -1432,6 +1492,8 @@ int imgdiff(int argc, const char** argv) {
if (name == "block-limit" && !android::base::ParseUint(optarg, &blocks_limit)) {
printf("failed to parse size blocks_limit: %s\n", optarg);
return 1;
+ } else if (name == "split-info") {
+ split_info_file = optarg;
} else if (name == "debug-dir") {
debug_dir = optarg;
}
@@ -1451,6 +1513,8 @@ int imgdiff(int argc, const char** argv) {
" --block-limit, For large zips, split the src and tgt based on the block limit;\n"
" and generate patches between each pair of pieces. Concatenate these\n"
" patches together and output them into <patch-file>.\n"
+ " --split-info, Output the split information (patch_size, tgt_size, src_ranges);\n"
+ " zip mode with block-limit only.\n"
" --debug_dir, Debug directory to put the split srcs and patches, zip mode only.\n");
return 2;
}
@@ -1476,6 +1540,11 @@ int imgdiff(int argc, const char** argv) {
// Compute bsdiff patches for each chunk's data (the uncompressed data, in the case of
// deflate chunks).
if (blocks_limit > 0) {
+ if (split_info_file.empty()) {
+ printf("split-info path cannot be empty when generating patches with a block-limit.\n");
+ return 1;
+ }
+
std::vector<ZipModeImage> split_tgt_images;
std::vector<ZipModeImage> split_src_images;
std::vector<SortedRangeSet> split_src_ranges;
@@ -1483,7 +1552,7 @@ int imgdiff(int argc, const char** argv) {
&split_src_images, &split_src_ranges);
if (!ZipModeImage::GeneratePatches(split_tgt_images, split_src_images, split_src_ranges,
- argv[optind + 2], debug_dir)) {
+ argv[optind + 2], split_info_file, debug_dir)) {
return 1;
}
diff --git a/applypatch/include/applypatch/imgdiff_image.h b/applypatch/include/applypatch/imgdiff_image.h
index 9fb844b24..491043dc1 100644
--- a/applypatch/include/applypatch/imgdiff_image.h
+++ b/applypatch/include/applypatch/imgdiff_image.h
@@ -132,6 +132,9 @@ class PatchChunk {
// Update the source start with the new offset within the source range.
void UpdateSourceOffset(const SortedRangeSet& src_range);
+ // Return the total size (header + data) of the patch.
+ size_t PatchSize() const;
+
static bool WritePatchDataToFd(const std::vector<PatchChunk>& patch_chunks, int patch_fd);
private:
@@ -241,7 +244,8 @@ class ZipModeImage : public Image {
static bool GeneratePatches(const std::vector<ZipModeImage>& split_tgt_images,
const std::vector<ZipModeImage>& split_src_images,
const std::vector<SortedRangeSet>& split_src_ranges,
- const std::string& patch_name, const std::string& debug_dir);
+ const std::string& patch_name, const std::string& split_info_file,
+ const std::string& debug_dir);
// Split the tgt chunks and src chunks based on the size limit.
static bool SplitZipModeImageWithLimit(const ZipModeImage& tgt_image,
diff --git a/tests/component/imgdiff_test.cpp b/tests/component/imgdiff_test.cpp
index 73516050b..161d58d45 100644
--- a/tests/component/imgdiff_test.cpp
+++ b/tests/component/imgdiff_test.cpp
@@ -778,11 +778,13 @@ TEST(ImgdiffTest, zip_mode_store_large_apk) {
// Compute patch.
TemporaryFile patch_file;
+ TemporaryFile split_info_file;
TemporaryDir debug_dir;
+ std::string split_info_arg = android::base::StringPrintf("--split-info=%s", split_info_file.path);
std::string debug_dir_arg = android::base::StringPrintf("--debug-dir=%s", debug_dir.path);
std::vector<const char*> args = {
- "imgdiff", "-z", "--block-limit=10", debug_dir_arg.c_str(), src_file.path, tgt_file.path,
- patch_file.path,
+ "imgdiff", "-z", "--block-limit=10", split_info_arg.c_str(), debug_dir_arg.c_str(),
+ src_file.path, tgt_file.path, patch_file.path,
};
ASSERT_EQ(0, imgdiff(args.size(), args.data()));
@@ -864,14 +866,40 @@ TEST(ImgdiffTest, zip_mode_deflate_large_apk) {
// Compute patch.
TemporaryFile patch_file;
+ TemporaryFile split_info_file;
TemporaryDir debug_dir;
ASSERT_TRUE(ZipModeImage::GeneratePatches(split_tgt_images, split_src_images, split_src_ranges,
- patch_file.path, debug_dir.path));
+ patch_file.path, split_info_file.path, debug_dir.path));
+
+ // Verify the content of split info.
+ // Expect 5 pieces of patch. ["a","b"; "c"; "d-0"; "d-1"; "e"]
+ std::string split_info_string;
+ android::base::ReadFileToString(split_info_file.path, &split_info_string);
+ std::vector<std::string> info_list =
+ android::base::Split(android::base::Trim(split_info_string), "\n");
+
+ ASSERT_EQ(static_cast<size_t>(7), info_list.size());
+ ASSERT_EQ("2", android::base::Trim(info_list[0]));
+ ASSERT_EQ("5", android::base::Trim(info_list[1]));
+
+ std::vector<size_t> patch_size;
+ for (size_t i = 0; i < 5; i++) {
+ struct stat st = {};
+ std::string path = android::base::StringPrintf("%s/patch-%zu", debug_dir.path, i);
+ ASSERT_EQ(0, stat(path.c_str(), &st));
+ patch_size.push_back(st.st_size);
+ }
+
+ ASSERT_EQ(std::to_string(patch_size[0]) + " 36864 2,22,31", android::base::Trim(info_list[2]));
+ ASSERT_EQ(std::to_string(patch_size[1]) + " 32768 2,31,40", android::base::Trim(info_list[3]));
+ ASSERT_EQ(std::to_string(patch_size[2]) + " 40960 2,0,11", android::base::Trim(info_list[4]));
+ ASSERT_EQ(std::to_string(patch_size[3]) + " 40960 2,11,21", android::base::Trim(info_list[5]));
+ ASSERT_EQ(std::to_string(patch_size[4]) + " 8833 4,21,22,40,41",
+ android::base::Trim(info_list[6]));
std::string tgt;
ASSERT_TRUE(android::base::ReadFileToString(tgt_file.path, &tgt));
- // Expect 5 pieces of patch. ["a","b"; "c"; "d-0"; "d-1"; "e"]
GenerateAndCheckSplitTarget(debug_dir.path, 5, tgt);
}
@@ -901,11 +929,13 @@ TEST(ImgdiffTest, zip_mode_no_match_source) {
// Compute patch.
TemporaryFile patch_file;
+ TemporaryFile split_info_file;
TemporaryDir debug_dir;
+ std::string split_info_arg = android::base::StringPrintf("--split-info=%s", split_info_file.path);
std::string debug_dir_arg = android::base::StringPrintf("--debug-dir=%s", debug_dir.path);
std::vector<const char*> args = {
- "imgdiff", "-z", "--block-limit=10", debug_dir_arg.c_str(), src_file.path, tgt_file.path,
- patch_file.path,
+ "imgdiff", "-z", "--block-limit=10", debug_dir_arg.c_str(), split_info_arg.c_str(),
+ src_file.path, tgt_file.path, patch_file.path,
};
ASSERT_EQ(0, imgdiff(args.size(), args.data()));
@@ -941,11 +971,13 @@ TEST(ImgdiffTest, zip_mode_large_enough_limit) {
// Compute patch with a limit of 20 blocks.
TemporaryFile patch_file;
+ TemporaryFile split_info_file;
TemporaryDir debug_dir;
+ std::string split_info_arg = android::base::StringPrintf("--split-info=%s", split_info_file.path);
std::string debug_dir_arg = android::base::StringPrintf("--debug-dir=%s", debug_dir.path);
std::vector<const char*> args = {
- "imgdiff", "-z", "--block-limit=20", debug_dir_arg.c_str(), src_file.path, tgt_file.path,
- patch_file.path,
+ "imgdiff", "-z", "--block-limit=20", split_info_arg.c_str(), debug_dir_arg.c_str(),
+ src_file.path, tgt_file.path, patch_file.path,
};
ASSERT_EQ(0, imgdiff(args.size(), args.data()));
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 05:08:18 +0100