[MINOR] buffers: add peekchar and peekline functions for stream interfaces
The buffer_si_peekline() function is sort of a fgets() to be used from a
stream interface. It returns a complete line whenever possible, and does
not update the buffer's pointer, so that the reader is free to consume
what it wants to.
buffer_si_peekchar() only returns one character, and also needs a call
to buffer_skip() once the character is definitely consumed.
diff --git a/include/proto/buffers.h b/include/proto/buffers.h
index d4ae20b..544db65 100644
--- a/include/proto/buffers.h
+++ b/include/proto/buffers.h
@@ -347,8 +347,26 @@
buf->send_max -= len;
}
+/*
+ * Return one char from the buffer. If the buffer is empty and closed, return -1.
+ * If the buffer is just empty, return -2. The buffer's pointer is not advanced,
+ * it's up to the caller to call buffer_skip(buf, 1) when it has consumed the char.
+ * Also note that this function respects the send_max limit.
+ */
+static inline int buffer_si_peekchar(struct buffer *buf)
+{
+ if (buf->send_max)
+ return *buf->w;
+
+ if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
+ return -1;
+ else
+ return -2;
+}
+
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_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);
int buffer_insert_line2(struct buffer *b, char *pos, const char *str, int len);
diff --git a/src/buffers.c b/src/buffers.c
index 6d406c5..edda459 100644
--- a/src/buffers.c
+++ b/src/buffers.c
@@ -119,6 +119,55 @@
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.
+ * =0 : no '\n' before end found. <buf> is undefined.
+ * <0 : no more bytes readable + shutdown set.
+ * The buffer status is not changed. The caller must call buffer_skip() to
+ * update it. The '\n' 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 '\n'.
+ */
+int buffer_si_peekline(struct buffer *buf, char *str, int len)
+{
+ int ret, max;
+ char *p;
+
+ ret = 0;
+ max = len;
+ if (!buf->send_max) {
+ if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
+ ret = -1;
+ goto out;
+ }
+
+ p = buf->w;
+
+ if (max > buf->send_max) {
+ max = buf->send_max;
+ str[max] = 0;
+ }
+ while (max) {
+ *str++ = *p;
+ ret++;
+ max--;
+
+ if (*p == '\n')
+ break;
+ p++;
+ if (p == buf->data + buf->size)
+ p = buf->data;
+ }
+ if (*p != '\n' && ret < len && ret < buf->max_len &&
+ !(buf->flags & (BF_SHUTW|BF_SHUTW_NOW)))
+ ret = 0;
+ out:
+ if (max)
+ *str = 0;
+ return ret;
+}
+
/*
* this function writes the string <str> at position <pos> which must be in buffer <b>,
* and moves <end> just after the end of <str>.