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diff --git a/src/utils/strbuf.c b/src/utils/strbuf.c
index c8e7e633a27452ade2e8bdb85f078cb542e9e63f..d8a95ac42f60a4003d9cdf21924cbfbf2a5ccee1 100644 (file)
--- a/src/utils/strbuf.c
+++ b/src/utils/strbuf.c
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#include "sysdb.h"
#include "utils/strbuf.h"
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
+#include <string.h>
+
+#include <unistd.h>
+
+/* free memory if most of the buffer is unused */
+#define CHECK_SHRINK(buf) \
+ do { \
+ if (((buf)->pos < (buf)->size / 3) \
+ && (2 * (buf)->pos > (buf)->min_size)) \
+ /* don't free all memory to avoid churn */ \
+ strbuf_resize((buf), 2 * (buf)->pos); \
+ } while (0)
/*
* private data structures
char *string;
size_t size;
size_t pos;
+
+ /* min size to shrink the buffer to */
+ size_t min_size;
};
/*
*/
static int
-strbuf_resize(sdb_strbuf_t *strbuf, size_t new_size)
+strbuf_resize(sdb_strbuf_t *buf, size_t new_size)
{
+ size_t tmp_size;
char *tmp;
- if (new_size <= strbuf->size)
- return 0;
+ if (new_size <= buf->pos)
+ return -1;
- tmp = realloc(strbuf->string, new_size);
+ tmp_size = SDB_MAX(buf->size, buf->min_size);
+ if (! tmp_size)
+ tmp_size = 64;
+ while (tmp_size < new_size)
+ tmp_size *= 2;
+
+ tmp = realloc(buf->string, new_size);
if (! tmp)
return -1;
- strbuf->string = tmp;
- strbuf->size = new_size;
+ if (new_size)
+ buf->string = tmp;
+ else
+ buf->string = NULL;
+ buf->size = new_size;
return 0;
} /* strbuf_resize */
sdb_strbuf_t *
sdb_strbuf_create(size_t size)
{
- sdb_strbuf_t *strbuf;
+ sdb_strbuf_t *buf;
- strbuf = calloc(1, sizeof(*strbuf));
- if (! strbuf)
+ buf = calloc(1, sizeof(*buf));
+ if (! buf)
return NULL;
- strbuf->string = NULL;
+ buf->string = NULL;
if (size) {
- strbuf->string = malloc(size);
- if (! strbuf->string) {
- free(strbuf);
+ buf->string = malloc(size);
+ if (! buf->string) {
+ free(buf);
return NULL;
}
- strbuf->string[0] = '\0';
+ buf->string[0] = '\0';
+ buf->min_size = size;
}
+ else
+ buf->min_size = 64;
- strbuf->size = size;
- strbuf->pos = 0;
+ buf->size = size;
+ buf->pos = 0;
- return strbuf;
+ return buf;
} /* sdb_strbuf_create */
void
-sdb_strbuf_destroy(sdb_strbuf_t *strbuf)
+sdb_strbuf_destroy(sdb_strbuf_t *buf)
{
- if (! strbuf)
+ if (! buf)
return;
- if (strbuf->string)
- free(strbuf->string);
- free(strbuf);
+ if (buf->string)
+ free(buf->string);
+ free(buf);
} /* sdb_strbuf_destroy */
ssize_t
-sdb_strbuf_vappend(sdb_strbuf_t *strbuf, const char *fmt, va_list ap)
+sdb_strbuf_vappend(sdb_strbuf_t *buf, const char *fmt, va_list ap)
{
va_list aq;
int status;
- if ((! strbuf) || (! fmt))
+ if ((! buf) || (! fmt))
return -1;
- assert((strbuf->size == 0) || (strbuf->string[strbuf->pos] == '\0'));
+ assert((buf->size == 0) || (buf->string[buf->pos] == '\0'));
- if (strbuf->pos >= strbuf->size)
+ if (! buf->size) {
/* use some arbitrary but somewhat reasonable default */
- if (strbuf_resize(strbuf, strbuf->size ? 2 * strbuf->size : 64))
+ if (strbuf_resize(buf, 64))
+ return -1;
+ }
+ /* make sure to reserve space for the nul-byte */
+ else if (buf->pos >= buf->size - 1)
+ if (strbuf_resize(buf, 2 * buf->size))
return -1;
- assert(strbuf->size && strbuf->string);
- assert(strbuf->pos < strbuf->size);
+ assert(buf->size && buf->string);
+ assert(buf->pos < buf->size);
/* 'ap' is invalid after calling vsnprintf; thus copy before using it */
va_copy(aq, ap);
- status = vsnprintf(strbuf->string + strbuf->pos,
- strbuf->size - strbuf->pos, fmt, ap);
+ status = vsnprintf(buf->string + buf->pos,
+ buf->size - buf->pos, fmt, ap);
if (status < 0) {
va_end(aq);
return status;
}
- if ((size_t)status >= strbuf->size - strbuf->pos) {
- strbuf_resize(strbuf, (size_t)status + 1);
+ /* 'status' does not include nul-byte */
+ if ((size_t)status >= buf->size - buf->pos) {
+ if (strbuf_resize(buf, buf->pos + (size_t)status + 1)) {
+ va_end(aq);
+ return -1;
+ }
/* reset string and try again */
- strbuf->string[strbuf->pos] = '\0';
- status = (int)sdb_strbuf_vappend(strbuf, fmt, aq);
+ buf->string[buf->pos] = '\0';
+ status = (int)sdb_strbuf_vappend(buf, fmt, aq);
}
else
- strbuf->pos += (size_t)status;
+ buf->pos += (size_t)status;
va_end(aq);
+
+ /* even though this function always appends to the existing buffer, the
+ * size might have previously been reset */
+ CHECK_SHRINK(buf);
+
return (ssize_t)status;
} /* sdb_strbuf_vappend */
ssize_t
-sdb_strbuf_append(sdb_strbuf_t *strbuf, const char *fmt, ...)
+sdb_strbuf_append(sdb_strbuf_t *buf, const char *fmt, ...)
{
va_list ap;
ssize_t status;
va_start(ap, fmt);
- status = sdb_strbuf_vappend(strbuf, fmt, ap);
+ status = sdb_strbuf_vappend(buf, fmt, ap);
va_end(ap);
return status;
} /* sdb_strbuf_append */
ssize_t
-sdb_strbuf_vsprintf(sdb_strbuf_t *strbuf, const char *fmt, va_list ap)
+sdb_strbuf_vsprintf(sdb_strbuf_t *buf, const char *fmt, va_list ap)
{
- if (! strbuf)
+ if (! buf)
return -1;
- if (strbuf->size) {
- strbuf->string[0] = '\0';
- strbuf->pos = 0;
+ if (buf->size) {
+ buf->string[0] = '\0';
+ buf->pos = 0;
}
- return sdb_strbuf_vappend(strbuf, fmt, ap);
+ return sdb_strbuf_vappend(buf, fmt, ap);
} /* sdb_strbuf_vsprintf */
ssize_t
-sdb_strbuf_sprintf(sdb_strbuf_t *strbuf, const char *fmt, ...)
+sdb_strbuf_sprintf(sdb_strbuf_t *buf, const char *fmt, ...)
{
va_list ap;
ssize_t status;
va_start(ap, fmt);
- status = sdb_strbuf_vsprintf(strbuf, fmt, ap);
+ status = sdb_strbuf_vsprintf(buf, fmt, ap);
va_end(ap);
return status;
} /* sdb_strbuf_sprintf */
ssize_t
-sdb_strbuf_chomp(sdb_strbuf_t *strbuf)
+sdb_strbuf_memappend(sdb_strbuf_t *buf, const void *data, size_t n)
+{
+ if ((! buf) || (! data))
+ return -1;
+
+ assert((buf->size == 0) || (buf->string[buf->pos] == '\0'));
+
+ if (buf->pos + n + 1 > buf->size) {
+ if (strbuf_resize(buf, buf->pos + n + 1))
+ return -1;
+ }
+
+ assert(buf->size && buf->string);
+ assert(buf->pos < buf->size);
+
+ memcpy((void *)(buf->string + buf->pos), data, n);
+ buf->pos += n;
+ buf->string[buf->pos] = '\0';
+
+ /* even though this function always appends to the existing buffer, the
+ * size might have previously been reset */
+ CHECK_SHRINK(buf);
+
+ return (ssize_t)n;
+} /* sdb_strbuf_memappend */
+
+ssize_t
+sdb_strbuf_memcpy(sdb_strbuf_t *buf, const void *data, size_t n)
+{
+ if ((! buf) || (! data))
+ return -1;
+
+ if (buf->size) {
+ buf->string[0] = '\0';
+ buf->pos = 0;
+ }
+
+ return sdb_strbuf_memappend(buf, data, n);
+} /* sdb_strbuf_memcpy */
+
+ssize_t
+sdb_strbuf_read(sdb_strbuf_t *buf, int fd, size_t n)
+{
+ ssize_t ret;
+
+ if (! buf)
+ return -1;
+
+ if (buf->pos + n + 1 >= buf->size)
+ if (strbuf_resize(buf, buf->pos + n + 1))
+ return -1;
+
+ ret = read(fd, buf->string + buf->pos, n);
+ if (ret > 0)
+ buf->pos += (size_t)ret;
+ return ret;
+} /* sdb_strbuf_read */
+
+ssize_t
+sdb_strbuf_chomp(sdb_strbuf_t *buf)
{
ssize_t ret = 0;
- if (! strbuf)
+ if (! buf)
return -1;
- assert(strbuf->size || (strbuf->pos < strbuf->size));
- assert(strbuf->pos <= strbuf->size);
+ assert((!buf->size) || (buf->pos < buf->size));
+ assert(buf->pos <= buf->size);
- while ((strbuf->pos > 0)
- && (strbuf->string[strbuf->pos - 1] == '\n')) {
- --strbuf->pos;
- strbuf->string[strbuf->pos] = '\0';
+ while ((buf->pos > 0)
+ && (buf->string[buf->pos - 1] == '\n')) {
+ --buf->pos;
+ buf->string[buf->pos] = '\0';
++ret;
}
return ret;
} /* sdb_strbuf_chomp */
+void
+sdb_strbuf_skip(sdb_strbuf_t *buf, size_t offset, size_t n)
+{
+ char *start;
+ size_t len;
+
+ if ((! buf) || (! n))
+ return;
+
+ if (offset >= buf->pos)
+ return;
+
+ len = buf->pos - offset;
+
+ if (n >= len) {
+ buf->string[offset] = '\0';
+ buf->pos = offset;
+ return;
+ }
+
+ assert(offset + n < buf->pos);
+ assert(offset < buf->pos);
+
+ start = buf->string + offset;
+ memmove(start, start + n, len - n);
+ buf->pos -= n;
+ buf->string[buf->pos] = '\0';
+
+ /* don't resize now but wait for the next write to avoid churn */
+} /* sdb_strbuf_skip */
+
+void
+sdb_strbuf_clear(sdb_strbuf_t *buf)
+{
+ if ((! buf) || (! buf->size))
+ return;
+
+ buf->string[0] = '\0';
+ buf->pos = 0;
+
+ /* don't resize now but wait for the next write to avoid churn */
+} /* sdb_strbuf_clear */
+
const char *
-sdb_strbuf_string(sdb_strbuf_t *strbuf)
+sdb_strbuf_string(sdb_strbuf_t *buf)
{
- if (! strbuf)
+ if (! buf)
return NULL;
- if (! strbuf->size)
+ if (! buf->size)
return "";
- return strbuf->string;
+ return buf->string;
} /* sdb_strbuf_string */
size_t
-sdb_strbuf_len(sdb_strbuf_t *strbuf)
+sdb_strbuf_len(sdb_strbuf_t *buf)
{
- if (! strbuf)
+ if (! buf)
return 0;
- return strbuf->pos;
+ return buf->pos;
} /* sdb_strbuf_string */
+size_t
+sdb_strbuf_cap(sdb_strbuf_t *buf)
+{
+ if (! buf)
+ return 0;
+ return buf->size;
+} /* sdb_strbuf_cap */
+
/* vim: set tw=78 sw=4 ts=4 noexpandtab : */