AU: Delta Diff Generator
Adds a class that can take two root filesystem image and generate a
delta between them. Currently it's not very well tested, but this will
improve once the diff applicator is written.
Also, an executable to run the generator.
Other changes:
- Stop leaking loop devices in unittests
- extent mapper: support sparse files, ability to get FS block size
- AppendBlockToExtents support sparse files
- subprocess more verbose on errors
- add WriteAll to utils (WriteAll avoids short-write() returns)
- mkstemp wrapper for ease of use
- VectorIndexOf, finds index of an element in a vector
Review URL: http://codereview.chromium.org/891002
diff --git a/extent_mapper.cc b/extent_mapper.cc
index ed528fd..4af5f5d 100755
--- a/extent_mapper.cc
+++ b/extent_mapper.cc
@@ -16,6 +16,8 @@
#include <linux/fs.h>
+#include "update_engine/graph_types.h"
+#include "update_engine/graph_utils.h"
#include "update_engine/utils.h"
using std::string;
@@ -31,7 +33,6 @@
bool ExtentsForFileFibmap(const std::string& path, std::vector<Extent>* out) {
CHECK(out);
- // TODO(adlr): verify path is a file
struct stat stbuf;
int rc = stat(path.c_str(), &stbuf);
TEST_AND_RETURN_FALSE_ERRNO(rc == 0);
@@ -53,32 +54,23 @@
current.set_num_blocks(0);
for (int i = 0; i < block_count; i++) {
- unsigned int block = i;
- rc = ioctl(fd, FIBMAP, &block);
+ unsigned int block32 = i;
+ rc = ioctl(fd, FIBMAP, &block32);
TEST_AND_RETURN_FALSE_ERRNO(rc == 0);
- // Add next block to extents
- if (current.num_blocks() == 0) {
- // We're starting a new extent
- current.set_start_block(block);
- current.set_num_blocks(1);
- continue;
- }
- if ((current.start_block() + current.num_blocks()) == block) {
- // We're continuing the last extent
- current.set_num_blocks(current.num_blocks() + 1);
- continue;
- }
- // We're starting a new extent and keeping the current one
- out->push_back(current);
- current.set_start_block(block);
- current.set_num_blocks(1);
- continue;
+ const uint64 block = (block32 == 0 ? kSparseHole : block32);
+
+ graph_utils::AppendBlockToExtents(out, block);
}
-
- if (current.num_blocks() > 0)
- out->push_back(current);
+ return true;
+}
+bool GetFilesystemBlockSize(const std::string& path, uint32* out_blocksize) {
+ int fd = open(path.c_str(), O_RDONLY, 0);
+ TEST_AND_RETURN_FALSE_ERRNO(fd >= 0);
+ ScopedFdCloser fd_closer(&fd);
+ int rc = ioctl(fd, FIGETBSZ, out_blocksize);
+ TEST_AND_RETURN_FALSE_ERRNO(rc != -1);
return true;
}