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Improve speed of gzprintf() in transparent mode.

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This commit is contained in:
Mark Adler 2015-07-05 18:14:53 -07:00
parent 8a979f6c79
commit 95698093f0
4 changed files with 70 additions and 51 deletions
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2
gzguts.h
View File

@ -170,7 +170,7 @@ typedef struct {
char *path; /* path or fd for error messages */
unsigned size; /* buffer size, zero if not allocated yet */
unsigned want; /* requested buffer size, default is GZBUFSIZE */
unsigned char *in; /* input buffer */
unsigned char *in; /* input buffer (double-sized when writing) */
unsigned char *out; /* output buffer (double-sized when reading) */
int direct; /* 0 if processing gzip, 1 if transparent */
/* just for reading */

2
gzlib.c
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@ -331,6 +331,8 @@ int ZEXPORT gzbuffer(file, size)
return -1;
/* check and set requested size */
if ((size << 1) < size)
return -1; /* need to be able to double it */
if (size < 2)
size = 2; /* need two bytes to check magic header */
state->want = size;

110
gzwrite.c
View File

@ -18,8 +18,8 @@ local int gz_init(state)
int ret;
z_streamp strm = &(state->strm);
/* allocate input buffer */
state->in = (unsigned char *)malloc(state->want);
/* allocate input buffer (double size for gzprintf) */
state->in = (unsigned char *)malloc(state->want << 1);
if (state->in == NULL) {
gz_error(state, Z_MEM_ERROR, "out of memory");
return -1;
@ -309,7 +309,8 @@ int ZEXPORT gzputs(file, str)
/* -- see zlib.h -- */
int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
{
int size, len;
unsigned len, left;
char *next;
gz_statep state;
z_streamp strm;
@ -334,39 +335,47 @@ int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
return 0;
}
/* consume whatever's left in the input buffer */
if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
return 0;
/* do the printf() into the input buffer, put length in len */
size = (int)(state->size);
state->in[size - 1] = 0;
/* do the printf() into the input buffer, put length in len -- the input
buffer is double-sized just for this function, so there is guaranteed to
be state->size bytes available after the current contents */
if (strm->avail_in == 0)
strm->next_in = state->in;
next = (char *)(strm->next_in + strm->avail_in);
next[state->size - 1] = 0;
#ifdef NO_vsnprintf
# ifdef HAS_vsprintf_void
(void)vsprintf((char *)(state->in), format, va);
for (len = 0; len < size; len++)
if (state->in[len] == 0) break;
(void)vsprintf(next, format, va);
for (len = 0; len < state->size; len++)
if (next[len] == 0) break;
# else
len = vsprintf((char *)(state->in), format, va);
len = vsprintf(next, format, va);
# endif
#else
# ifdef HAS_vsnprintf_void
(void)vsnprintf((char *)(state->in), size, format, va);
len = strlen((char *)(state->in));
(void)vsnprintf(next, state->size, format, va);
len = strlen(next);
# else
len = vsnprintf((char *)(state->in), size, format, va);
len = vsnprintf(next, state->size, format, va);
# endif
#endif
/* check that printf() results fit in buffer */
if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
if (len == 0 || len >= state->size || next[state->size - 1] != 0)
return 0;
/* update buffer and position, defer compression until needed */
strm->avail_in = (unsigned)len;
strm->next_in = state->in;
/* update buffer and position, compress first half if past that */
strm->avail_in += len;
state->x.pos += len;
return len;
if (strm->avail_in >= state->size) {
left = strm->avail_in - state->size;
strm->avail_in = state->size;
if (gz_comp(state, Z_NO_FLUSH) == -1)
return 0;
memcpy(state->in, state->in + state->size, left);
strm->next_in = state->in;
strm->avail_in = left;
}
return (int)len;
}
int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
@ -390,7 +399,8 @@ int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
{
int size, len;
unsigned len, left;
char *next;
gz_statep state;
z_streamp strm;
@ -419,44 +429,52 @@ int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
return 0;
}
/* consume whatever's left in the input buffer */
if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
return 0;
/* do the printf() into the input buffer, put length in len */
size = (int)(state->size);
state->in[size - 1] = 0;
/* do the printf() into the input buffer, put length in len -- the input
buffer is double-sized just for this function, so there is guaranteed to
be state->size bytes available after the current contents */
if (strm->avail_in == 0)
strm->next_in = state->in;
next = (char *)(strm->next_in + strm->avail_in);
next[state->size - 1] = 0;
#ifdef NO_snprintf
# ifdef HAS_sprintf_void
sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
a13, a14, a15, a16, a17, a18, a19, a20);
for (len = 0; len < size; len++)
if (state->in[len] == 0) break;
if (next[len] == 0)
break;
# else
len = sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
a12, a13, a14, a15, a16, a17, a18, a19, a20);
# endif
#else
# ifdef HAS_snprintf_void
snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6, a7, a8,
a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
len = strlen((char *)(state->in));
snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
len = strlen(next);
# else
len = snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6,
a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18,
a19, a20);
len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
# endif
#endif
/* check that printf() results fit in buffer */
if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
if (len == 0 || len >= state->size || next[state->size - 1] != 0)
return 0;
/* update buffer and position, defer compression until needed */
strm->avail_in = (unsigned)len;
strm->next_in = state->in;
/* update buffer and position, compress first half if past that */
strm->avail_in += len;
state->x.pos += len;
return len;
if (strm->avail_in >= state->size) {
left = strm->avail_in - state->size;
strm->avail_in = state->size;
if (gz_comp(state, Z_NO_FLUSH) == -1)
return 0;
memcpy(state->in, state->in + state->size, left);
strm->next_in = state->in;
strm->avail_in = left;
}
return (int)len;
}
#endif

7
zlib.h
View File

@ -1291,10 +1291,9 @@ ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
default buffer size is 8192 bytes. This function must be called after
gzopen() or gzdopen(), and before any other calls that read or write the
file. The buffer memory allocation is always deferred to the first read or
write. Two buffers are allocated, either both of the specified size when
writing, or one of the specified size and the other twice that size when
reading. A larger buffer size of, for example, 64K or 128K bytes will
noticeably increase the speed of decompression (reading).
write. Three times that size in buffer space is allocated. A larger buffer
size of, for example, 64K or 128K bytes will noticeably increase the speed
of decompression (reading).
The new buffer size also affects the maximum length for gzprintf().