From: Lars Schneider <larsxschneider@xxxxxxxxx>
Sometimes pkt-line data is already available in a buffer and it would
be a waste of resources to write the packet using packet_write() which
would copy the existing buffer into a strbuf before writing it.
If the caller has control over the buffer creation then the
PKTLINE_DATA_START macro can be used to skip the header and write
directly into the data section of a pkt-line (PKTLINE_DATA_LEN bytes
would be the maximum). direct_packet_write() would take this buffer,
adjust the pkt-line header and write it.
If the caller has no control over the buffer creation then
direct_packet_write_data() can be used. This function creates a pkt-line
header. Afterwards the header and the data buffer are written using two
consecutive write calls.
Both functions have a gentle parameter that indicates if Git should die
in case of a write error (gentle set to 0) or return with a error (gentle
set to 1).
Signed-off-by: Lars Schneider <larsxschneider@xxxxxxxxx>
---
pkt-line.c | 42 ++++++++++++++++++++++++++++++++++++++++++
pkt-line.h | 5 +++++
2 files changed, 47 insertions(+)
diff --git a/pkt-line.c b/pkt-line.c
index 177dc73..aa158ba 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -136,6 +136,48 @@ void packet_write(int fd, const char *fmt, ...)
write_or_die(fd, buf.buf, buf.len);
}
+int direct_packet_write(int fd, char *buf, size_t size, int gentle)
+{
+ int ret = 0;
+ if (size > LARGE_PACKET_MAX) {
+ if (gentle)
+ return 0;
+ else
+ die("protocol error: impossibly long line");
+ }
+ packet_trace(buf + 4, size - 4, 1);
+ set_packet_header(buf, size);
+ if (gentle)
+ ret = !write_or_whine_pipe(fd, buf, size, "pkt-line");
+ else
+ write_or_die(fd, buf, size);
+ return ret;
+}
+
+int direct_packet_write_data(int fd, const char *data, size_t size, int gentle)
+{
+ int ret = 0;
+ char hdr[PKTLINE_HEADER_LEN];
+ if (size > PKTLINE_DATA_MAXLEN) {
+ if (gentle)
+ return 0;
+ else
+ die("protocol error: impossibly long line");
+ }
+ set_packet_header(hdr, PKTLINE_HEADER_LEN + size);
+ packet_trace(data, size, 1);
+ if (gentle) {
+ ret = (
+ !write_or_whine_pipe(fd, hdr, PKTLINE_HEADER_LEN, "pkt-line header") ||
+ !write_or_whine_pipe(fd, data, size, "pkt-line data")
+ );
+ } else {
+ write_or_die(fd, hdr, PKTLINE_HEADER_LEN);
+ write_or_die(fd, data, size);
+ }
+ return ret;
+}
+
void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
{
va_list args;
diff --git a/pkt-line.h b/pkt-line.h
index 3cb9d91..ed64511 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -23,6 +23,8 @@ 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 direct_packet_write(int fd, char *buf, size_t size, int gentle);
+int direct_packet_write_data(int fd, const char *data, size_t size, int gentle);
/*
* Read a packetized line into the buffer, which must be at least size bytes
@@ -77,6 +79,9 @@ char *packet_read_line_buf(char **src_buf, size_t *src_len, int *size);
#define DEFAULT_PACKET_MAX 1000
#define LARGE_PACKET_MAX 65520
+#define PKTLINE_HEADER_LEN 4
+#define PKTLINE_DATA_START(pkt) ((pkt) + PKTLINE_HEADER_LEN)
+#define PKTLINE_DATA_MAXLEN (LARGE_PACKET_MAX - PKTLINE_HEADER_LEN)
extern char packet_buffer[LARGE_PACKET_MAX];
#endif
--
2.9.0
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html