Create read_or_die utility routine.

Like write_or_die read_or_die reads the entire length requested
or it kills the current process with a die call.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/cache.h b/cache.h
index cc872440ef85d9bead5df72879eba2bfe0b84347..e6b716495d615a351213f5f8dbc437d7136443b0 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -428,6 +428,7 @@ extern char *git_commit_encoding;
 extern char *git_log_output_encoding;
 
 extern int copy_fd(int ifd, int ofd);
+extern void read_or_die(int fd, void *buf, size_t count);
 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);
 

diff --git a/write_or_die.c b/write_or_die.c
index bfe4eeb6494c7076bf7f319cf11628f586142aa5..8cf6486025a0fffba889618ce07a0d4eadd139df 100644 (file)
--- a/write_or_die.c
+++ b/write_or_die.c
@@ -1,5 +1,21 @@
 #include "cache.h"
 
+void read_or_die(int fd, void *buf, size_t count)
+{
+       char *p = buf;
+       ssize_t loaded;
+
+       while (count > 0) {
+               loaded = xread(fd, p, count);
+               if (loaded == 0)
+                       die("unexpected end of file");
+               else if (loaded < 0)
+                       die("read error (%s)", strerror(errno));
+               count -= loaded;
+               p += loaded;
+       }
+}
+
 void write_or_die(int fd, const void *buf, size_t count)
 {
        const char *p = buf;