[MINOR] buffers: provide buffer_si_putchar() to send a char from a stream interface
This function works like a traditional putchar() except that it
can return 0 if the output buffer is full.
Now a basic character-based echo function would look like this, from
a stream interface :
while (1) {
c = buffer_si_peekchar(req);
if (c < 0)
break;
if (!buffer_si_putchar(res, c)) {
si->flags |= SI_FL_WAIT_ROOM;
break;
}
buffer_skip(req, 1);
req->flags |= BF_WRITE_PARTIAL;
res->flags |= BF_READ_PARTIAL;
}
diff --git a/include/proto/buffers.h b/include/proto/buffers.h
index 544db65..724d148 100644
--- a/include/proto/buffers.h
+++ b/include/proto/buffers.h
@@ -366,6 +366,7 @@
int buffer_write(struct buffer *buf, const char *msg, int len);
int buffer_feed(struct buffer *buf, const char *str, int len);
+int buffer_si_putchar(struct buffer *buf, char c);
int buffer_si_peekline(struct buffer *buf, char *str, int len);
int buffer_replace(struct buffer *b, char *pos, char *end, const char *str);
int buffer_replace2(struct buffer *b, char *pos, char *end, const char *str, int len);
diff --git a/src/buffers.c b/src/buffers.c
index edda459..ee7a5dc 100644
--- a/src/buffers.c
+++ b/src/buffers.c
@@ -119,6 +119,38 @@
return -1;
}
+/* Try to write character <c> into buffer <buf> after length controls. This
+ * work like buffer_feed(buf, &c, 1).
+ * Returns non-zero in case of success, 0 if the buffer was full.
+ * The send limit is automatically adjusted with the amount of data written.
+ */
+int buffer_si_putchar(struct buffer *buf, char c)
+{
+ if (buf->flags & BF_FULL)
+ return 0;
+
+ if (!buf->l)
+ buf->r = buf->w = buf->lr = buf->data;
+
+ *buf->r++ = c;
+ buf->l++;
+ buf->total++;
+
+ if (buf->to_forward) {
+ buf->send_max++;
+ buf->to_forward--;
+ }
+
+ if (buf->r == buf->data + buf->size)
+ buf->r = buf->data;
+
+ buf->flags &= ~(BF_EMPTY|BF_FULL);
+ if (buf->l >= buf->max_len)
+ buf->flags |= BF_FULL;
+
+ return 1;
+}
+
/* Get one text line out of a buffer from a stream interface.
* Return values :
* >0 : number of bytes read. Includes the \n if present before len or end.