/**
* @file util_varbuf.h
* @brief Apache resizable variable length buffer library
+ *
+ * This set of functions provides resizable buffers. While the primary
+ * usage is with NUL-terminated strings, most functions also work with
+ * arbitrary binary data.
+ *
+ * @defgroup APACHE_CORE_VARBUF
+ * @ingroup APACHE_CORE
+ * @{
*/
#ifndef AP_VARBUF_H
/** A resizable buffer */
struct ap_varbuf {
- /** the actual buffer; will point to a const '\0' if avail == 0 */
+ /** the actual buffer; will point to a const '\0' if avail == 0 and
+ * to memory of the same lifetime as the pool otherwise */
char *buf;
/** allocated size of the buffer (minus one for the final \0);
apr_size_t strlen;
/** the pool for memory allocations and for registering the cleanup;
- * the buffer memory will be released when this pool is destroyed */
+ * the buffer memory will be released when this pool is cleared */
apr_pool_t *pool;
/** opaque info for memory allocation */
/** initialize a resizable buffer. It is safe to re-initialize a prevously
* used ap_varbuf. The old buffer will be released when the corresponding
- * pool is destroyed.
+ * pool is cleared. The buffer remains usable until the pool is cleared,
+ * even if the ap_varbuf was located on the stack and has gone out of scope.
* @param pool the pool to allocate small buffers from and to register the
* cleanup with
* @param vb pointer to the ap_varbuf struct
apr_size_t init_size);
/** grow a resizable buffer. If the vb->buf cannot be grown in place, it will
- * be reallocated and up to vb->strlen + 1 bytes of memory will be copied to
- * the new location. If vb->strlen == AP_VARBUF_UNKNOWN, the whole buffer
+ * be reallocated and the first vb->strlen + 1 bytes of memory will be copied
+ * to the new location. If vb->strlen == AP_VARBUF_UNKNOWN, the whole buffer
* is copied.
* @param vb pointer to the ap_varbuf struct
* @param new_size the minimum new size of the buffer
/** Release memory from a ap_varbuf immediately, if possible.
* This allows to free large buffers before the corresponding pool is
- * destroyed. Only larger allocations using mem nodes will be freed.
+ * cleared. Only larger allocations using mem nodes will be freed.
* @param vb pointer to the ap_varbuf struct
* @note After ap_varbuf_free(), vb must not be used unless ap_varbuf_init()
* is called again.
*/
AP_DECLARE(void) ap_varbuf_free(struct ap_varbuf *vb);
-/** Concatenate a string to an ap_varbuf
+/** Concatenate a string to an ap_varbuf. vb->strlen determines where
+ * the string is appended in the buffer. If vb->strlen == AP_VARBUF_UNKNOWN,
+ * the string will be appended at the first NUL byte in the buffer.
+ * If len == 0, ap_varbuf_strmemcat() does nothing.
* @param vb pointer to the ap_varbuf struct
* @param str the string to append; must be at least len bytes long
* @param len the number of characters of *str to concatenate to the buf
* @note vb->strlen will be set to the length of the new string
- * @note vb->buf will be null-terminated
+ * @note if len != 0, vb->buf will always be NUL-terminated
*/
AP_DECLARE(void) ap_varbuf_strmemcat(struct ap_varbuf *vb, const char *str,
int len);
* @return the new string
* @note ap_varbuf_pdup() uses vb->strlen to determine how much memory to
* copy. It works even if 0-bytes are embedded in vb->buf, prepend, or
- * append
+ * append.
+ * @note If vb->strlen equals AP_VARBUF_UNKNOWN, it will be set to
+ * strlen(vb->buf).
*/
AP_DECLARE(char *) ap_varbuf_pdup(apr_pool_t *p, struct ap_varbuf *vb,
const char *prepend, apr_size_t prepend_len,
* @note Just like ap_pregsub(), this function does not copy the part of
* *source before the matching part (i.e. the first pmatch[0].rm_so
* characters).
+ * @note If vb->strlen equals AP_VARBUF_UNKNOWN, it will be set to
+ * strlen(vb->buf) first.
*/
AP_DECLARE(apr_status_t) ap_varbuf_regsub(struct ap_varbuf *vb,
const char *input,
ap_regmatch_t pmatch[],
apr_size_t maxlen);
-/** Read a line from an ap_configfile_t into an ap_varbuf.
+/** Read a line from an ap_configfile_t and append it to an ap_varbuf.
* @param vb pointer to the ap_varbuf struct
* @param cfg pointer to the ap_configfile_t
* @param max_len maximum line length, including leading/trailing whitespace
* @return see ap_cfg_getline()
* @note vb->strlen will be set to the length of the line
+ * @note If vb->strlen equals AP_VARBUF_UNKNOWN, it will be set to
+ * strlen(vb->buf) first.
*/
AP_DECLARE(apr_status_t) ap_varbuf_cfg_getline(struct ap_varbuf *vb,
ap_configfile_t *cfp,
#endif
#endif /* !AP_VARBUF_H */
+/** @} */
*result = dst = apr_palloc(p, len + 1);
}
else {
- if (vb->buf && vb->strlen == AP_VARBUF_UNKNOWN)
+ if (vb->strlen == AP_VARBUF_UNKNOWN)
vb->strlen = strlen(vb->buf);
ap_varbuf_grow(vb, vb->strlen + len);
dst = vb->buf + vb->strlen;
apr_size_t max_len)
{
apr_status_t rc;
+ apr_size_t new_len;
vb->strlen = 0;
*vb->buf = '\0';
+ if (vb->strlen == AP_VARBUF_UNKNOWN)
+ vb->strlen = strlen(vb->buf);
+ if (vb->avail - vb->strlen < 3) {
+ new_len = vb->avail * 2;
+ if (new_len > max_len)
+ new_len = max_len;
+ else if (new_len < 3)
+ new_len = 3;
+ ap_varbuf_grow(vb, new_len);
+ }
+
for (;;) {
- apr_size_t new_len;
rc = ap_cfg_getline_core(vb->buf + vb->strlen, vb->avail - vb->strlen, cfp);
if (rc == APR_ENOSPC || rc == APR_SUCCESS)
vb->strlen += strlen(vb->buf + vb->strlen);
struct ap_varbuf_info *new_info;
char *new;
+ AP_DEBUG_ASSERT(vb->strlen == AP_VARBUF_UNKNOWN || vb->avail >= vb->strlen);
+
if (new_len <= vb->avail)
return;
i++;
}
if (buf->avail && buf->strlen) {
+ if (buf->strlen == AP_VARBUF_UNKNOWN)
+ buf->strlen = strlen(buf->buf);
vec[i].iov_base = (void *)buf->buf;
- vec[i].iov_len = (buf->strlen == AP_VARBUF_UNKNOWN) ? buf->avail
- : buf->strlen;
+ vec[i].iov_len = buf->strlen;
i++;
}
if (append) {
projects / apache / commitdiff