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| author | Takayuki MATSUOKA <takayuki.matsuoka@gmail.com> | 2015-02-12 11:18:16 (GMT) |
|---|---|---|
| committer | Takayuki MATSUOKA <takayuki.matsuoka@gmail.com> | 2015-03-02 04:38:27 (GMT) |
| commit | b372f45093aa8d86f7a99b7dd5e2deaeffb10033 (patch) | |
| tree | 4a9dac1d3aa046f560677d1ec01a35128e3caa1b /programs/lz4io.c | |
| parent | 01a24afdcf867a901076eaa87434b3dcb39d526f (diff) | |
| download | lz4-b372f45093aa8d86f7a99b7dd5e2deaeffb10033.zip lz4-b372f45093aa8d86f7a99b7dd5e2deaeffb10033.tar.gz lz4-b372f45093aa8d86f7a99b7dd5e2deaeffb10033.tar.bz2 | |
Add Neil's method to isSparse()
Diffstat (limited to 'programs/lz4io.c')
| -rw-r--r-- | programs/lz4io.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/programs/lz4io.c b/programs/lz4io.c index b1067ac..c69275d 100644 --- a/programs/lz4io.c +++ b/programs/lz4io.c @@ -220,6 +220,7 @@ int LZ4IO_setSparseFile(int yes) static int isSparse(const void* p, size_t size) { #if 0 + /* naive */ const char* p8 = p; for(; size; --size) { @@ -230,7 +231,8 @@ static int isSparse(const void* p, size_t size) ++p8; } return 1; -#else +#elif 0 + /* xz method */ const U64* p64 = (const U64*) p; const char* p8 = (const char*) p; const size_t n = size / sizeof(*p64); @@ -253,6 +255,10 @@ static int isSparse(const void* p, size_t size) } return 1; +#else + /* Neil's */ + const char* buf = (const char*) p; + return buf[0] == 0 && !memcmp(buf, buf + 1, size - 1); #endif } #endif /* LZ4IO_ENABLE_SPARSE_FILE */ |