diff options
| -rw-r--r-- | include/util/util.h | 8 | ||||
| -rw-r--r-- | lib/sqfs/Makemodule.am | 2 | ||||
| -rw-r--r-- | lib/sqfs/block_writer.c | 59 | ||||
| -rw-r--r-- | lib/util/Makemodule.am | 1 | ||||
| -rw-r--r-- | lib/util/file_cmp.c | 41 |
5 files changed, 65 insertions, 46 deletions
diff --git a/include/util/util.h b/include/util/util.h index 6e34a82..0161c2b 100644 --- a/include/util/util.h +++ b/include/util/util.h @@ -69,4 +69,12 @@ SQFS_INTERNAL bool is_filename_sane(const char *name, bool check_os_specific); */ SQFS_INTERNAL sqfs_u32 get_source_date_epoch(void); +/* + Check if two regions in a file are equal using a scratch buffer to load the + data into for comparision. Returns 0 if equal, > 0 if not, < 0 if error. + */ +SQFS_INTERNAL int check_file_range_equal(sqfs_file_t *file, void *scratch, + size_t scratch_size, sqfs_u64 loc_a, + sqfs_u64 loc_b, sqfs_u64 size); + #endif /* SQFS_UTIL_H */ diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am index ad3d42d..b1c9d94 100644 --- a/lib/sqfs/Makemodule.am +++ b/lib/sqfs/Makemodule.am @@ -44,7 +44,7 @@ libsquashfs_la_LIBADD += $(ZSTD_LIBS) $(PTHREAD_LIBS) # directly "import" stuff from libutil libsquashfs_la_SOURCES += lib/util/str_table.c lib/util/alloc.c -libsquashfs_la_SOURCES += lib/util/xxhash.c +libsquashfs_la_SOURCES += lib/util/xxhash.c lib/util/file_cmp.c libsquashfs_la_SOURCES += lib/util/hash_table.c include/util/hash_table.h libsquashfs_la_SOURCES += lib/util/rbtree.c include/util/rbtree.h libsquashfs_la_SOURCES += lib/util/array.c include/util/array.h diff --git a/lib/sqfs/block_writer.c b/lib/sqfs/block_writer.c index 10f5ada..7709fb3 100644 --- a/lib/sqfs/block_writer.c +++ b/lib/sqfs/block_writer.c @@ -54,44 +54,20 @@ static int store_block_location(block_writer_default_t *wr, sqfs_u64 offset, return array_append(&(wr->blocks), &info); } -static int compare_blocks(block_writer_default_t *wr, sqfs_u64 loc_a, - sqfs_u64 loc_b, size_t size) -{ - sqfs_u8 *ptr_a = wr->scratch, *ptr_b = ptr_a + SCRATCH_SIZE / 2; - size_t diff; - int ret; - - while (size > 0) { - diff = SCRATCH_SIZE / 2; - diff = diff > size ? size : diff; - - ret = wr->file->read_at(wr->file, loc_a, ptr_a, diff); - if (ret != 0) - return ret; - - ret = wr->file->read_at(wr->file, loc_b, ptr_b, diff); - if (ret != 0) - return ret; - - if (memcmp(ptr_a, ptr_b, diff) != 0) - return 1; - - size -= diff; - loc_a += diff; - loc_b += diff; - } - - return 0; -} - static int deduplicate_blocks(block_writer_default_t *wr, size_t count, size_t *out) { const blk_info_t *blocks = wr->blocks.data; - sqfs_u64 loc_a, loc_b; - size_t i, j, sz; + sqfs_u64 loc_a, loc_b, sz; + size_t i, j; int ret; + sz = 0; + loc_a = blocks[wr->file_start].offset; + + for (i = 0; i < count; ++i) + sz += SIZE_FROM_HASH(blocks[wr->file_start + i].hash); + for (i = 0; i < wr->file_start; ++i) { for (j = 0; j < count; ++j) { if (blocks[i + j].hash == 0) @@ -108,21 +84,14 @@ static int deduplicate_blocks(block_writer_default_t *wr, size_t count, if (wr->flags & SQFS_BLOCK_WRITER_HASH_COMPARE_ONLY) break; - for (j = 0; j < count; ++j) { - sz = SIZE_FROM_HASH(blocks[i + j].hash); + loc_b = blocks[i].offset; - loc_a = blocks[i + j].offset; - loc_b = blocks[wr->file_start + j].offset; - - ret = compare_blocks(wr, loc_a, loc_b, sz); - if (ret < 0) - return ret; - if (ret > 0) - break; - } - - if (j == count) + ret = check_file_range_equal(wr->file, wr->scratch, + SCRATCH_SIZE, loc_a, loc_b, sz); + if (ret == 0) break; + if (ret < 0) + return ret; } *out = i; diff --git a/lib/util/Makemodule.am b/lib/util/Makemodule.am index b65ebda..830a338 100644 --- a/lib/util/Makemodule.am +++ b/lib/util/Makemodule.am @@ -13,6 +13,7 @@ libutil_a_SOURCES += lib/util/mkdir_p.c libutil_a_SOURCES += lib/util/canonicalize_name.c libutil_a_SOURCES += lib/util/filename_sane.c libutil_a_SOURCES += lib/util/source_date_epoch.c +libutil_a_SOURCES += lib/util/file_cmp.c libutil_a_CFLAGS = $(AM_CFLAGS) libutil_a_CPPFLAGS = $(AM_CPPFLAGS) diff --git a/lib/util/file_cmp.c b/lib/util/file_cmp.c new file mode 100644 index 0000000..2aa0cc2 --- /dev/null +++ b/lib/util/file_cmp.c @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: LGPL-3.0-or-later */ +/* + * file_cmp.c + * + * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at> + */ +#include "config.h" + +#include "util/util.h" +#include "sqfs/io.h" + +#include <string.h> + +int check_file_range_equal(sqfs_file_t *file, void *scratch, size_t scratch_sz, + sqfs_u64 loc_a, sqfs_u64 loc_b, sqfs_u64 size) +{ + sqfs_u8 *ptr_a = scratch, *ptr_b = ptr_a + scratch_sz / 2; + int ret; + + while (size > 0) { + size_t diff = scratch_sz / 2; + diff = (sqfs_u64)diff > size ? size : diff; + + ret = file->read_at(file, loc_a, ptr_a, diff); + if (ret != 0) + return ret; + + ret = file->read_at(file, loc_b, ptr_b, diff); + if (ret != 0) + return ret; + + if (memcmp(ptr_a, ptr_b, diff) != 0) + return 1; + + size -= diff; + loc_a += diff; + loc_b += diff; + } + + return 0; +} |