[MEDIUM] buffers: rework the functions to exchange between SI and buffers

There was no consistency between all the functions used to exchange data
between a buffer and a stream interface. Also, the functions used to send
data to a buffer did not consider the possibility that the buffer was
shutdown for read.

Now the functions are called buffer_{put,get}_{char,block,chunk,string}.

The old buffer_feed* functions have been left available for existing code
but marked deprecated.
diff --git a/include/proto/buffers.h b/include/proto/buffers.h
index dca3c88..8ae2a7f 100644
--- a/include/proto/buffers.h
+++ b/include/proto/buffers.h
@@ -39,6 +39,18 @@
 /* perform minimal intializations, report 0 in case of error, 1 if OK. */
 int init_buffer();
 
+/* SI-to-buffer functions : buffer_{get,put}_{char,block,string,chunk} */
+int buffer_write(struct buffer *buf, const char *msg, int len);
+int buffer_put_block(struct buffer *buf, const char *str, int len);
+int buffer_put_char(struct buffer *buf, char c);
+int buffer_get_line(struct buffer *buf, char *str, int len);
+int buffer_get_block(struct buffer *buf, char *blk, int len, int offset);
+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);
+void buffer_dump(FILE *o, struct buffer *b, int from, int to);
+void buffer_bounce_realign(struct buffer *buf);
+
 /* Initialize all fields in the buffer. The BF_OUT_EMPTY flags is set. */
 static inline void buffer_init(struct buffer *buf)
 {
@@ -65,6 +77,18 @@
 		return buf->size - global.tune.maxrewrite + buf->to_forward + buf->send_max;
 }
 
+/* Returns true if the buffer's input is already closed */
+static inline int buffer_input_closed(struct buffer *buf)
+{
+	return ((buf->flags & BF_SHUTR) != 0);
+}
+
+/* Returns true if the buffer's output is already closed */
+static inline int buffer_output_closed(struct buffer *buf)
+{
+	return ((buf->flags & BF_SHUTW) != 0);
+}
+
 /* Check buffer timeouts, and set the corresponding flags. The
  * likely/unlikely have been optimized for fastest normal path.
  * The read/write timeouts are not set if there was activity on the buffer.
@@ -291,7 +315,7 @@
 
 /*
  * Return the maximum amount of bytes that can be written into the buffer in
- * one call to buffer_feed*().
+ * one call to buffer_put_*().
  */
 static inline int buffer_free_space(struct buffer *buf)
 {
@@ -406,66 +430,6 @@
 	buf->flags |= BF_WRITE_PARTIAL;
 }
 
-/*
- * 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;
-}
-
-/* Try to write character <c> into buffer <buf> after length controls. This
- * work like buffer_feed2(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.
- */
-static inline int buffer_si_putchar(struct buffer *buf, char c)
-{
-	if (buf->flags & BF_FULL)
-		return 0;
-
-	*buf->r = c;
-
-	buf->l++;
-	if (buf->l >= buffer_max_len(buf))
-		buf->flags |= BF_FULL;
-
-	buf->r++;
-	if (buf->r - buf->data == buf->size)
-		buf->r -= buf->size;
-
-	if (buf->to_forward >= 1) {
-		if (buf->to_forward != BUF_INFINITE_FORWARD)
-			buf->to_forward--;
-		buf->send_max++;
-		buf->flags &= ~BF_OUT_EMPTY;
-	}
-
-	buf->total++;
-	return 1;
-}
-
-int buffer_write(struct buffer *buf, const char *msg, int len);
-int buffer_feed2(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);
-int buffer_insert_line2(struct buffer *b, char *pos, const char *str, int len);
-void buffer_dump(FILE *o, struct buffer *b, int from, int to);
-void buffer_bounce_realign(struct buffer *buf);
-
-
-
 /* writes the chunk <chunk> to buffer <buf>. Returns -1 in case of success,
  * -2 if it is larger than the buffer size, or the number of bytes available
  * otherwise. If the chunk has been written, its size is automatically reset
@@ -482,35 +446,91 @@
 	return ret;
 }
 
-/* Try to write chunk <chunk> into buffer <buf> after length controls. This is
- * the equivalent of buffer_write_chunk() except that to_forward and send_max
- * are updated and that max_len is respected. Returns -1 in case of success,
- * -2 if it is larger than the buffer size, or the number of bytes available
- * otherwise. If the chunk has been written, its size is automatically reset
- * to zero. The send limit is automatically adjusted with the amount of data
- * written.
+/* Tries to copy chunk <chunk> into buffer <buf> after length controls.
+ * The send_max and to_forward pointers are updated. If the buffer's input is
+ * closed, -2 is returned. If the block is too large for this buffer, -3 is
+ * returned. If there is not enough room left in the buffer, -1 is returned.
+ * Otherwise the number of bytes copied is returned (0 being a valid number).
+ * Buffer flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
+ * transferred. The chunk's length is updated with the number of bytes sent.
  */
-static inline int buffer_feed_chunk(struct buffer *buf, struct chunk *chunk)
+static inline int buffer_put_chunk(struct buffer *buf, struct chunk *chunk)
 {
 	int ret;
 
-	ret = buffer_feed2(buf, chunk->str, chunk->len);
-	if (ret == -1)
-		chunk->len = 0;
+	ret = buffer_put_block(buf, chunk->str, chunk->len);
+	if (ret > 0)
+		chunk->len -= ret;
 	return ret;
 }
 
-/* Try to write string <str> into buffer <buf> after length controls. This is
- * the equivalent of buffer_feed2() except that string length is measured by
- * the function. Returns -1 in case of success, -2 if it is larger than the
- * buffer size, or the number of bytes available otherwise. The send limit is
- * automatically adjusted with the amount of data written.
+/* Tries to copy string <str> at once into buffer <buf> after length controls.
+ * The send_max and to_forward pointers are updated. If the buffer's input is
+ * closed, -2 is returned. If the block is too large for this buffer, -3 is
+ * returned. If there is not enough room left in the buffer, -1 is returned.
+ * Otherwise the number of bytes copied is returned (0 being a valid number).
+ * Buffer flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
+ * transferred.
+ */
+static inline int buffer_put_string(struct buffer *buf, const char *str)
+{
+	return buffer_put_block(buf, str, strlen(str));
+}
+
+/*
+ * Return one char from the buffer. If the buffer is empty and closed, return -2.
+ * If the buffer is just empty, return -1. 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_get_char(struct buffer *buf)
+{
+	/* closed or empty + imminent close = -2; empty = -1 */
+	if (unlikely(buf->flags & (BF_OUT_EMPTY|BF_SHUTW))) {
+		if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
+			return -2;
+		return -1;
+	}
+	return *buf->w;
+}
+
+
+/* DEPRECATED, just provided for compatibility, use buffer_put_chunk() instead !!!
+ * returns >= 0 if the buffer is too small to hold the message, -1 if the
+ * transfer was OK, -2 in case of failure.
+ */
+static inline int buffer_feed_chunk(struct buffer *buf, struct chunk *msg)
+{
+	int ret = buffer_put_chunk(buf, msg);
+	if (ret >= 0) /* transfer OK */
+		return -1;
+	if (ret == -1) /* missing room */
+		return 1;
+	/* failure */
+	return -2;
+}
+
+/* DEPRECATED, just provided for compatibility, use buffer_put_string() instead !!!
+ * returns >= 0 if the buffer is too small to hold the message, -1 if the
+ * transfer was OK, -2 in case of failure.
  */
 static inline int buffer_feed(struct buffer *buf, const char *str)
 {
-	return buffer_feed2(buf, str, strlen(str));
+	int ret = buffer_put_string(buf, str);
+	if (ret >= 0) /* transfer OK */
+		return -1;
+	if (ret == -1) /* missing room */
+		return 1;
+	/* failure */
+	return -2;
 }
 
+/*
+ *
+ * Functions below are used to manage chunks
+ *
+ */
+
 static inline void chunk_init(struct chunk *chk, char *str, size_t size) {
 	chk->str  = str;
 	chk->len  = 0;
diff --git a/src/buffers.c b/src/buffers.c
index c128bb9..1572a37 100644
--- a/src/buffers.c
+++ b/src/buffers.c
@@ -72,37 +72,78 @@
 	return -1;
 }
 
-/* Try to write string <str> into buffer <buf> after length controls. This
- * is the equivalent of buffer_write() except that to_forward and send_max
- * are updated and that max_len is respected. Returns -1 in case of success,
- * -2 if it is larger than the buffer size, or the number of bytes available
- * otherwise. The send limit is automatically adjusted with the amount of data
- * written.
+/* Tries to copy character <c> into buffer <buf> after length controls. The
+ * send_max and to_forward pointers are updated. If the buffer's input is
+ * closed, -2 is returned. If there is not enough room left in the buffer, -1
+ * is returned. Otherwise the number of bytes copied is returned (1). Buffer
+ * flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
+ * transferred.
  */
-int buffer_feed2(struct buffer *buf, const char *str, int len)
+int buffer_put_char(struct buffer *buf, char c)
 {
-	int max;
+	if (unlikely(buffer_input_closed(buf)))
+		return -2;
 
-	if (len == 0)
+	if (buf->flags & BF_FULL)
 		return -1;
 
+	*buf->r = c;
+
+	buf->l++;
+	if (buf->l >= buffer_max_len(buf))
+		buf->flags |= BF_FULL;
+	buf->flags |= BF_READ_PARTIAL;
+
+	buf->r++;
+	if (buf->r - buf->data == buf->size)
+		buf->r -= buf->size;
+
+	if (buf->to_forward >= 1) {
+		if (buf->to_forward != BUF_INFINITE_FORWARD)
+			buf->to_forward--;
+		buf->send_max++;
+		buf->flags &= ~BF_OUT_EMPTY;
+	}
+
+	buf->total++;
+	return 1;
+}
+
+/* Tries to copy block <blk> at once into buffer <buf> after length controls.
+ * The send_max and to_forward pointers are updated. If the buffer's input is
+ * closed, -2 is returned. If the block is too large for this buffer, -3 is
+ * returned. If there is not enough room left in the buffer, -1 is returned.
+ * Otherwise the number of bytes copied is returned (0 being a valid number).
+ * Buffer flags FULL, EMPTY and READ_PARTIAL are updated if some data can be
+ * transferred.
+ */
+int buffer_put_block(struct buffer *buf, const char *blk, int len)
+{
+	int max;
+
+	if (unlikely(buffer_input_closed(buf)))
+		return -2;
+
 	max = buffer_max_len(buf);
-	if (len > max - buf->l) {
+	if (unlikely(len > max - buf->l)) {
 		/* we can't write this chunk right now because the buffer is
 		 * almost full or because the block is too large. Return the
 		 * available space or -2 if impossible.
 		 */
 		if (len > max)
-			return -2;
+			return -3;
 
-		return max - buf->l;
+		return -1;
 	}
 
+	if (unlikely(len == 0))
+		return 0;
+
 	/* OK so the data fits in the buffer in one or two blocks */
 	max = buffer_contig_space_with_len(buf, max);
-	memcpy(buf->r, str, MIN(len, max));
+	memcpy(buf->r, blk, MIN(len, max));
 	if (len > max)
-		memcpy(buf->data, str + max, len - max);
+		memcpy(buf->data, blk + max, len - max);
 
 	buf->l += len;
 	buf->r += len;
@@ -127,27 +168,29 @@
 
 	/* notify that some data was read from the SI into the buffer */
 	buf->flags |= BF_READ_PARTIAL;
-	return -1;
+	return len;
 }
 
-/* Get one text line out of a buffer from a stream interface.
+/* Gets 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.
+ *   =0 : no '\n' before end found. <str> is left undefined.
+ *   <0 : no more bytes readable because output is shut.
  * 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 buffer_get_line(struct buffer *buf, char *str, int len)
 {
 	int ret, max;
 	char *p;
 
 	ret = 0;
 	max = len;
-	if (!buf->send_max) {
+
+	/* closed or empty + imminent close = -1; empty = 0 */
+	if (unlikely(buf->flags & (BF_OUT_EMPTY|BF_SHUTW))) {
 		if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
 			ret = -1;
 		goto out;
@@ -180,6 +223,43 @@
 	return ret;
 }
 
+/* Gets one full block of data at once from a buffer, optionally from a
+ * specific offset. Return values :
+ *   >0 : number of bytes read, equal to requested size.
+ *   =0 : not enough data available. <blk> is left undefined.
+ *   <0 : no more bytes readable because output is shut.
+ * The buffer status is not changed. The caller must call buffer_skip() to
+ * update it.
+ */
+int buffer_get_block(struct buffer *buf, char *blk, int len, int offset)
+{
+	int firstblock;
+
+	if (buf->flags & BF_SHUTW)
+		return -1;
+
+	if (len + offset > buf->send_max) {
+		if (buf->flags & (BF_SHUTW|BF_SHUTW_NOW))
+			return -1;
+		return 0;
+	}
+
+	firstblock = buf->data + buf->size - buf->w;
+	if (firstblock > offset) {
+		if (firstblock >= len + offset) {
+			memcpy(blk, buf->w + offset, len);
+			return len;
+		}
+
+		memcpy(blk, buf->w + offset, firstblock - offset);
+		memcpy(blk + firstblock - offset, buf->data, len - firstblock + offset);
+		return len;
+	}
+
+	memcpy(blk, buf->data + offset - firstblock, len);
+	return len;
+}
+
 /*
  * this function writes the string <str> at position <pos> which must be in buffer <b>,
  * and moves <end> just after the end of <str>.
diff --git a/src/dumpstats.c b/src/dumpstats.c
index aa5b02f..59607f9 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -858,7 +858,7 @@
 			if (buffer_almost_full(si->ib))
 				break;
 
-			reql = buffer_si_peekline(si->ob, trash, sizeof(trash));
+			reql = buffer_get_line(si->ob, trash, sizeof(trash));
 			if (reql <= 0) { /* closed or EOL not found */
 				if (reql == 0)
 					break;