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| author | Maxim Sobolev <sobomax@FreeBSD.org> | 2018-12-17 15:19:48 +0000 |
|---|---|---|
| committer | Maxim Sobolev <sobomax@FreeBSD.org> | 2018-12-17 15:19:48 +0000 |
| commit | cb0eeacd5cae048caf284a9072b8575eff536c40 (patch) | |
| tree | 0bc099094b91b705f5ae9837ea5a83a7fc42fede /bin | |
| parent | 8bc9303fd848d28d8a65449c918e7068def9026d (diff) | |
| download | src-cb0eeacd5cae048caf284a9072b8575eff536c40.tar.gz src-cb0eeacd5cae048caf284a9072b8575eff536c40.zip | |
MFC r341257: improve speed of empty block detection.
Notes
Notes:
svn path=/stable/11/; revision=342167
Diffstat (limited to 'bin')
| -rw-r--r-- | bin/dd/dd.c | 10 | ||||
| -rw-r--r-- | bin/dd/dd.h | 4 |
2 files changed, 7 insertions, 7 deletions
diff --git a/bin/dd/dd.c b/bin/dd/dd.c index c3392b695088..6443c9168ef4 100644 --- a/bin/dd/dd.c +++ b/bin/dd/dd.c @@ -474,7 +474,7 @@ void dd_out(int force) { u_char *outp; - size_t cnt, i, n; + size_t cnt, n; ssize_t nw; static int warned; int sparse; @@ -507,12 +507,8 @@ dd_out(int force) do { sparse = 0; if (ddflags & C_SPARSE) { - sparse = 1; /* Is buffer sparse? */ - for (i = 0; i < cnt; i++) - if (outp[i] != 0) { - sparse = 0; - break; - } + /* Is buffer sparse? */ + sparse = BISZERO(outp, cnt); } if (sparse && !force) { pending += cnt; diff --git a/bin/dd/dd.h b/bin/dd/dd.h index 7054d9cd0df9..796b2acf35cf 100644 --- a/bin/dd/dd.h +++ b/bin/dd/dd.h @@ -102,3 +102,7 @@ typedef struct { #define C_PROGRESS 0x40000000 #define C_PARITY (C_PAREVEN | C_PARODD | C_PARNONE | C_PARSET) + +#define BISZERO(p, s) ((s) > 0 && *((const char *)p) == 0 && !memcmp( \ + (const void *)(p), (const void *) \ + ((const char *)p + 1), (s) - 1)) |