MINOR: channel: add new function co_getdelim() to support multiple delimiters
For now we have co_getline() which reads a buffer and stops on LF, and
co_getword() which reads a buffer and stops on one arbitrary delimiter.
But sometimes we'd need to stop on a set of delimiters (CR and LF, etc).
This patch adds a new function co_getdelim() which takes a set of delimiters
as a string, and constructs a small map (32 bytes) that's looked up during
parsing to stop after the first delimiter found within the set. It also
supports an optional escape character that skips a delimiter (typically a
backslash). For the rest it works exactly like the two other variants.
diff --git a/include/haproxy/channel.h b/include/haproxy/channel.h
index abc1de1..07127bd 100644
--- a/include/haproxy/channel.h
+++ b/include/haproxy/channel.h
@@ -48,6 +48,7 @@
int co_inject(struct channel *chn, const char *msg, int len);
int co_getchar(const struct channel *chn, char *c);
int co_getline(const struct channel *chn, char *str, int len);
+int co_getdelim(const struct channel *chn, char *str, int len, const char *delim, char escape);
int co_getword(const struct channel *chn, char *str, int len, char sep);
int co_getblk(const struct channel *chn, char *blk, int len, int offset);
int co_getline_nc(const struct channel *chn, const char **blk1, size_t *len1, const char **blk2, size_t *len2);
diff --git a/src/channel.c b/src/channel.c
index c324673..524d104 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -176,6 +176,90 @@
return len;
}
+/* Locates the longest part of the channel's output buffer that is composed
+ * exclusively of characters not in the <delim> set, and delimited by one of
+ * these characters, and returns the initial part and the first of such
+ * delimiters. A single escape character in <escape> may be specified so that
+ * when not 0 and found, the character that follows it is never taken as a
+ * delimiter. Note that <delim> cannot contain the zero byte, hence this
+ * function is not usable with byte zero as a delimiter.
+ *
+ * Return values :
+ * >0 : number of bytes read. Includes the sep if present before len or end.
+ * =0 : no sep before end found. <str> is left undefined.
+ * <0 : no more bytes readable because output is shut.
+ * The channel status is not changed. The caller must call co_skip() to
+ * update it. One of the delimiters is waited for as long as neither the buffer
+ * nor the output are full. If either of them is full, the string may be
+ * returned as is, without the delimiter.
+ */
+int co_getdelim(const struct channel *chn, char *str, int len, const char *delim, char escape)
+{
+ uchar delim_map[256 / 8];
+ int found, escaped;
+ uint pos, bit;
+ int ret, max;
+ uchar b;
+ char *p;
+
+ ret = 0;
+ max = len;
+
+ /* closed or empty + imminent close = -1; empty = 0 */
+ if (unlikely((chn->flags & CF_SHUTW) || channel_is_empty(chn))) {
+ if (chn->flags & (CF_SHUTW|CF_SHUTW_NOW))
+ ret = -1;
+ goto out;
+ }
+
+ p = co_head(chn);
+
+ if (max > co_data(chn)) {
+ max = co_data(chn);
+ str[max-1] = 0;
+ }
+
+ /* create the byte map */
+ memset(delim_map, 0, sizeof(delim_map));
+ while ((b = *delim)) {
+ pos = b >> 3;
+ bit = b & 7;
+ delim_map[pos] |= 1 << bit;
+ delim++;
+ }
+
+ found = escaped = 0;
+ while (max) {
+ *str++ = b = *p;
+ ret++;
+ max--;
+
+ if (escape && (escaped || *p == escape)) {
+ escaped = !escaped;
+ goto skip;
+ }
+
+ pos = b >> 3;
+ bit = b & 7;
+ if (delim_map[pos] & (1 << bit)) {
+ found = 1;
+ break;
+ }
+ skip:
+ p = b_next(&chn->buf, p);
+ }
+
+ if (ret > 0 && ret < len &&
+ (ret < co_data(chn) || channel_may_recv(chn)) &&
+ !found &&
+ !(chn->flags & (CF_SHUTW|CF_SHUTW_NOW)))
+ ret = 0;
+ out:
+ if (max)
+ *str = 0;
+ return ret;
+}
+
/* Gets one text word out of a channel's buffer from a stream interface.
* Return values :
* >0 : number of bytes read. Includes the sep if present before len or end.