Trace into a file or an open fd and refactor tracing code.

If GIT_TRACE is set to an absolute path (starting with a
'/' character), we interpret this as a file path and we
trace into it.

Also if GIT_TRACE is set to an integer value greater than
1 and lower than 10, we interpret this as an open fd value
and we trace into it.

Note that this behavior is not compatible with the
previous one.

We also trace whole messages using one write(2) call to
make sure messages from processes do net get mixed up in
the middle.

This patch makes it possible to get trace information when
running "make test".

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index 7257c4c53..195908fc3 100644
--- a/cache.h
+++ b/cache.h
@@ -398,6 +398,7 @@ extern char git_commit_encoding[MAX_ENCODING_LENGTH];
 
 extern int copy_fd(int ifd, int ofd);
 extern void write_or_die(int fd, const void *buf, size_t count);
+extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
 
 /* Finish off pack transfer receiving end */
 extern int receive_unpack_pack(int fd[2], const char *me, int quiet, int);
@@ -423,4 +424,9 @@ extern struct commit *alloc_commit_node(void);
 extern struct tag *alloc_tag_node(void);
 extern void alloc_report(void);
 
+/* trace.c */
+extern int nfvasprintf(char **str, const char *fmt, va_list va);
+extern void trace_printf(const char *format, ...);
+extern void trace_argv_printf(const char **argv, int count, const char *format, ...);
+
 #endif /* CACHE_H */