1 files changed, 98 insertions, 16 deletions

diff --git a/wrapper.c b/wrapper.c
index 0cc56368bd..25074d71b6 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -9,16 +9,23 @@ static void do_nothing(size_t size)
 
 static void (*try_to_free_routine)(size_t size) = do_nothing;
 
-static void memory_limit_check(size_t size)
+static int memory_limit_check(size_t size, int gentle)
 {
 	static int limit = -1;
 	if (limit == -1) {
 		const char *env = getenv("GIT_ALLOC_LIMIT");
 		limit = env ? atoi(env) * 1024 : 0;
 	}
-	if (limit && size > limit)
-		die("attempting to allocate %"PRIuMAX" over limit %d",
-		    (intmax_t)size, limit);
+	if (limit && size > limit) {
+		if (gentle) {
+			error("attempting to allocate %"PRIuMAX" over limit %d",
+			      (intmax_t)size, limit);
+			return -1;
+		} else
+			die("attempting to allocate %"PRIuMAX" over limit %d",
+			    (intmax_t)size, limit);
+	}
+	return 0;
 }
 
 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
@@ -42,11 +49,12 @@ char *xstrdup(const char *str)
 	return ret;
 }
 
-void *xmalloc(size_t size)
+static void *do_xmalloc(size_t size, int gentle)
 {
 	void *ret;
 
-	memory_limit_check(size);
+	if (memory_limit_check(size, gentle))
+		return NULL;
 	ret = malloc(size);
 	if (!ret && !size)
 		ret = malloc(1);
@@ -55,9 +63,16 @@ void *xmalloc(size_t size)
 		ret = malloc(size);
 		if (!ret && !size)
 			ret = malloc(1);
-		if (!ret)
-			die("Out of memory, malloc failed (tried to allocate %lu bytes)",
-			    (unsigned long)size);
+		if (!ret) {
+			if (!gentle)
+				die("Out of memory, malloc failed (tried to allocate %lu bytes)",
+				    (unsigned long)size);
+			else {
+				error("Out of memory, malloc failed (tried to allocate %lu bytes)",
+				      (unsigned long)size);
+				return NULL;
+			}
+		}
 	}
 #ifdef XMALLOC_POISON
 	memset(ret, 0xA5, size);
@@ -65,16 +80,37 @@ void *xmalloc(size_t size)
 	return ret;
 }
 
-void *xmallocz(size_t size)
+void *xmalloc(size_t size)
+{
+	return do_xmalloc(size, 0);
+}
+
+static void *do_xmallocz(size_t size, int gentle)
 {
 	void *ret;
-	if (unsigned_add_overflows(size, 1))
-		die("Data too large to fit into virtual memory space.");
-	ret = xmalloc(size + 1);
-	((char*)ret)[size] = 0;
+	if (unsigned_add_overflows(size, 1)) {
+		if (gentle) {
+			error("Data too large to fit into virtual memory space.");
+			return NULL;
+		} else
+			die("Data too large to fit into virtual memory space.");
+	}
+	ret = do_xmalloc(size + 1, gentle);
+	if (ret)
+		((char*)ret)[size] = 0;
 	return ret;
 }
 
+void *xmallocz(size_t size)
+{
+	return do_xmallocz(size, 0);
+}
+
+void *xmallocz_gently(size_t size)
+{
+	return do_xmallocz(size, 1);
+}
+
 /*
  * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
  * "data" to the allocated memory, zero terminates the allocated memory,
@@ -96,7 +132,7 @@ void *xrealloc(void *ptr, size_t size)
 {
 	void *ret;
 
-	memory_limit_check(size);
+	memory_limit_check(size, 0);
 	ret = realloc(ptr, size);
 	if (!ret && !size)
 		ret = realloc(ptr, 1);
@@ -115,7 +151,7 @@ void *xcalloc(size_t nmemb, size_t size)
 {
 	void *ret;
 
-	memory_limit_check(size * nmemb);
+	memory_limit_check(size * nmemb, 0);
 	ret = calloc(nmemb, size);
 	if (!ret && (!nmemb || !size))
 		ret = calloc(1, 1);
@@ -174,6 +210,24 @@ ssize_t xwrite(int fd, const void *buf, size_t len)
 	}
 }
 
+/*
+ * xpread() is the same as pread(), but it automatically restarts pread()
+ * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
+ * NOT GUARANTEE that "len" bytes is read even if the data is available.
+ */
+ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
+{
+	ssize_t nr;
+	if (len > MAX_IO_SIZE)
+		len = MAX_IO_SIZE;
+	while (1) {
+		nr = pread(fd, buf, len, offset);
+		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
+			continue;
+		return nr;
+	}
+}
+
 ssize_t read_in_full(int fd, void *buf, size_t count)
 {
 	char *p = buf;
@@ -214,6 +268,26 @@ ssize_t write_in_full(int fd, const void *buf, size_t count)
 	return total;
 }
 
+ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
+{
+	char *p = buf;
+	ssize_t total = 0;
+
+	while (count > 0) {
+		ssize_t loaded = xpread(fd, p, count, offset);
+		if (loaded < 0)
+			return -1;
+		if (loaded == 0)
+			return total;
+		count -= loaded;
+		p += loaded;
+		total += loaded;
+		offset += loaded;
+	}
+
+	return total;
+}
+
 int xdup(int fd)
 {
 	int ret = dup(fd);
@@ -455,3 +529,11 @@ struct passwd *xgetpwuid_self(void)
 		    errno ? strerror(errno) : _("no such user"));
 	return pw;
 }
+
+char *xgetcwd(void)
+{
+	struct strbuf sb = STRBUF_INIT;
+	if (strbuf_getcwd(&sb))
+		die_errno(_("unable to get current working directory"));
+	return strbuf_detach(&sb, NULL);
+}