pkt-line: Add strbuf based functions

These routines help to work with pkt-line values inside of a strbuf,
permitting simple formatting of buffered network messages.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/pkt-line.c b/pkt-line.c
index b691abebd79b40f096b28b5dbcb433f01bc0e949..bd603f8721704305c2ce4608a09df38ed4bc55a0 100644 (file)
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -42,17 +42,19 @@ void packet_flush(int fd)
        safe_write(fd, "0000", 4);
 }
 
+void packet_buf_flush(struct strbuf *buf)
+{
+       strbuf_add(buf, "0000", 4);
+}
+
 #define hex(a) (hexchar[(a) & 15])
-void packet_write(int fd, const char *fmt, ...)
+static char buffer[1000];
+static unsigned format_packet(const char *fmt, va_list args)
 {
-       static char buffer[1000];
        static char hexchar[] = "0123456789abcdef";
-       va_list args;
        unsigned n;
 
-       va_start(args, fmt);
        n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
-       va_end(args);
        if (n >= sizeof(buffer)-4)
                die("protocol error: impossibly long line");
        n += 4;
@@ -60,9 +62,31 @@ void packet_write(int fd, const char *fmt, ...)
        buffer[1] = hex(n >> 8);
        buffer[2] = hex(n >> 4);
        buffer[3] = hex(n);
+       return n;
+}
+
+void packet_write(int fd, const char *fmt, ...)
+{
+       va_list args;
+       unsigned n;
+
+       va_start(args, fmt);
+       n = format_packet(fmt, args);
+       va_end(args);
        safe_write(fd, buffer, n);
 }
 
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
+{
+       va_list args;
+       unsigned n;
+
+       va_start(args, fmt);
+       n = format_packet(fmt, args);
+       va_end(args);
+       strbuf_add(buf, buffer, n);
+}
+
 static void safe_read(int fd, void *buffer, unsigned size)
 {
        ssize_t ret = read_in_full(fd, buffer, size);
@@ -72,15 +96,11 @@ static void safe_read(int fd, void *buffer, unsigned size)
                die("The remote end hung up unexpectedly");
 }
 
-int packet_read_line(int fd, char *buffer, unsigned size)
+static int packet_length(const char *linelen)
 {
        int n;
-       unsigned len;
-       char linelen[4];
-
-       safe_read(fd, linelen, 4);
+       int len = 0;
 
-       len = 0;
        for (n = 0; n < 4; n++) {
                unsigned char c = linelen[n];
                len <<= 4;
@@ -96,8 +116,20 @@ int packet_read_line(int fd, char *buffer, unsigned size)
                        len += c - 'A' + 10;
                        continue;
                }
-               die("protocol error: bad line length character");
+               return -1;
        }
+       return len;
+}
+
+int packet_read_line(int fd, char *buffer, unsigned size)
+{
+       int len;
+       char linelen[4];
+
+       safe_read(fd, linelen, 4);
+       len = packet_length(linelen);
+       if (len < 0)
+               die("protocol error: bad line length character");
        if (!len)
                return 0;
        len -= 4;
@@ -107,3 +139,31 @@ int packet_read_line(int fd, char *buffer, unsigned size)
        buffer[len] = 0;
        return len;
 }
+
+int packet_get_line(struct strbuf *out,
+       char **src_buf, size_t *src_len)
+{
+       int len;
+
+       if (*src_len < 4)
+               return -1;
+       len = packet_length(*src_buf);
+       if (len < 0)
+               return -1;
+       if (!len) {
+               *src_buf += 4;
+               *src_len -= 4;
+               return 0;
+       }
+       if (*src_len < len)
+               return -2;
+
+       *src_buf += 4;
+       *src_len -= 4;
+       len -= 4;
+
+       strbuf_add(out, *src_buf, len);
+       *src_buf += len;
+       *src_len -= len;
+       return len;
+}

diff --git a/pkt-line.h b/pkt-line.h
index 9df653f6f5afe720870658d7093bddbf3e66beaf..1e5dcfe87c568eaa7746091b1eb059834f4913bb 100644 (file)
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -2,14 +2,18 @@
 #define PKTLINE_H
 
 #include "git-compat-util.h"
+#include "strbuf.h"
 
 /*
  * Silly packetized line writing interface
  */
 void packet_flush(int fd);
 void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+void packet_buf_flush(struct strbuf *buf);
+void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
 
 int packet_read_line(int fd, char *buffer, unsigned size);
+int packet_get_line(struct strbuf *out, char **src_buf, size_t *src_len);
 ssize_t safe_write(int, const void *, ssize_t);
 
 #endif