From: Willy Tarreau <w@1wt.eu>
Date: Fri, 22 Sep 2017 13:47:51 +0000 (+0200)
Subject: MINOR: buffer: add two functions to inject data into buffers
X-Git-Tag: v1.8-dev3~31
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e5676e71034a26e338552702e7100b99806b1538;p=thirdparty%2Fhaproxy.git

MINOR: buffer: add two functions to inject data into buffers

bi_istput() injects the ist string into the input region of the buffer,
it will be used to feed small data chunks into the conn_stream. bo_istput()
does the same into the output region of the buffer, it will be used to send
data via the transport layer and assumes there's no input data.
---

diff --git a/include/common/buffer.h b/include/common/buffer.h
index 8050b1a36f..339de377b3 100644
--- a/include/common/buffer.h
+++ b/include/common/buffer.h
@@ -618,6 +618,64 @@ static inline int bi_eat(struct buffer *b, const struct ist ist)
 	return ret;
 }
 
+/* injects string <ist> into the input region of buffer <b> provided that it
+ * fits. Wrapping is supported. It's designed for small strings as it only
+ * writes a single byte per iteration. Returns the number of characters copied
+ * (ist.len), 0 if it temporarily does not fit or -1 if it will never fit. It
+ * will only modify the buffer upon success. In all cases, the contents are
+ * copied prior to reporting an error, so that the destination at least
+ * contains a valid but truncated string.
+ */
+static inline int bi_istput(struct buffer *b, const struct ist ist)
+{
+	const char *end = b->data + b->size;
+	struct ist r = ist;
+	char *p;
+
+	if (r.len > (size_t)(b->size - b->i - b->o))
+		return r.len < b->size ? 0 : -1;
+
+	p = b_ptr(b, b->i);
+	b->i += r.len;
+	while (r.len--) {
+		*p++ = *r.ptr++;
+		if (unlikely(p == end))
+			p = b->data;
+	}
+	return ist.len;
+}
+
+
+/* injects string <ist> into the output region of buffer <b> provided that it
+ * fits. Input data is assumed not to exist and will silently be overwritten.
+ * Wrapping is supported. It's designed for small strings as it only writes a
+ * single byte per iteration. Returns the number of characters copied (ist.len),
+ * 0 if it temporarily does not fit or -1 if it will never fit. It will only
+ * modify the buffer upon success. In all cases, the contents are copied prior
+ * to reporting an error, so that the destination at least contains a valid
+ * but truncated string.
+ */
+static inline int bo_istput(struct buffer *b, const struct ist ist)
+{
+	const char *end = b->data + b->size;
+	struct ist r = ist;
+	char *p;
+
+	if (r.len > (size_t)(b->size - b->o))
+		return r.len < b->size ? 0 : -1;
+
+	p = b->p;
+	b->o += r.len;
+	b->p = b_ptr(b, r.len);
+	while (r.len--) {
+		*p++ = *r.ptr++;
+		if (unlikely(p == end))
+			p = b->data;
+	}
+	return ist.len;
+}
+
+
 #endif /* _COMMON_BUFFER_H */
 
 /*