trace: add infrastructure to augment trace output with additional info

diff --git a/trace.c b/trace.c
index 8662b7980133eb900fde3bbb675e7a363f04cf1f..3d02bcc2393ae58e3af23c7566555ad04208ea49 100644 (file)
--- a/trace.c
+++ b/trace.c
@@ -85,17 +85,37 @@ void trace_disable(struct trace_key *key)
 static const char err_msg[] = "Could not trace into fd given by "
        "GIT_TRACE environment variable";
 
+static int prepare_trace_line(struct trace_key *key, struct strbuf *buf)
+{
+       if (!trace_want(key))
+               return 0;
+
+       set_try_to_free_routine(NULL);  /* is never reset */
+
+       /* add line prefix here */
+
+       return 1;
+}
+
+static void print_trace_line(struct trace_key *key, struct strbuf *buf)
+{
+       /* append newline if missing */
+       if (buf->len && buf->buf[buf->len - 1] != '\n')
+               strbuf_addch(buf, '\n');
+
+       write_or_whine_pipe(get_trace_fd(key), buf->buf, buf->len, err_msg);
+       strbuf_release(buf);
+}
+
 static void trace_vprintf(struct trace_key *key, const char *format, va_list ap)
 {
        struct strbuf buf = STRBUF_INIT;
 
-       if (!trace_want(key))
+       if (!prepare_trace_line(key, &buf))
                return;
 
-       set_try_to_free_routine(NULL);  /* is never reset */
        strbuf_vaddf(&buf, format, ap);
-       trace_strbuf(key, &buf);
-       strbuf_release(&buf);
+       print_trace_line(key, &buf);
 }
 
 void trace_printf_key(struct trace_key *key, const char *format, ...)
@@ -114,32 +134,31 @@ void trace_printf(const char *format, ...)
        va_end(ap);
 }
 
-void trace_strbuf(struct trace_key *key, const struct strbuf *buf)
+void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 {
-       int fd = get_trace_fd(key);
-       if (!fd)
+       struct strbuf buf = STRBUF_INIT;
+
+       if (!prepare_trace_line(key, &buf))
                return;
 
-       write_or_whine_pipe(fd, buf->buf, buf->len, err_msg);
+       strbuf_addbuf(&buf, data);
+       print_trace_line(key, &buf);
 }
 
 void trace_argv_printf(const char **argv, const char *format, ...)
 {
        struct strbuf buf = STRBUF_INIT;
        va_list ap;
-       int fd = get_trace_fd(NULL);
-       if (!fd)
+
+       if (!prepare_trace_line(NULL, &buf))
                return;
 
-       set_try_to_free_routine(NULL);  /* is never reset */
        va_start(ap, format);
        strbuf_vaddf(&buf, format, ap);
        va_end(ap);
 
        sq_quote_argv(&buf, argv, 0);
-       strbuf_addch(&buf, '\n');
-       write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
-       strbuf_release(&buf);
+       print_trace_line(NULL, &buf);
 }
 
 static const char *quote_crnl(const char *path)