From 14aa32dce539ac645ba10e8c488fb5a435ffa314 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Sun, 14 Apr 2013 20:21:25 +0200
Subject: [PATCH] Make read_tempfile() much faster, and make it close the file
 also on error.

---
 util.cpp | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/util.cpp b/util.cpp
index a5d6378..b79c6c3 100644
--- a/util.cpp
+++ b/util.cpp
@@ -41,27 +41,41 @@ int make_tempfile(const std::string &contents)
 
 bool read_tempfile(int fd, std::string *contents)
 {
+	bool ok = true;
+	ssize_t ret, has_read;
+
+	off_t len = lseek(fd, 0, SEEK_END);
+	if (len == -1) {
+		perror("lseek");
+		ok = false;
+		goto done;
+	}
+
+	contents->resize(len);
+
 	if (lseek(fd, 0, SEEK_SET) == -1) {
 		perror("lseek");
-		return false;
+		ok = false;
+		goto done;
 	}
 
-	char buf[4096];
-	for ( ;; ) {
-		ssize_t ret = read(fd, buf, sizeof(buf));
+	has_read = 0;
+	while (has_read < len) {
+		ret = read(fd, &((*contents)[has_read]), len - has_read);
 		if (ret == -1) {
 			perror("read");
-			return false;
+			ok = false;
+			goto done;
 		}
 		if (ret == 0) {
-			// EOF.
-			break;
+			fprintf(stderr, "Unexpected EOF!\n");
+			ok = false;
+			goto done;
 		}
-
-		contents->append(string(buf, buf + ret));
+		has_read += ret;
 	}
 
-	int ret;
+done:
 	do {
 		ret = close(fd);  // Implicitly deletes the files.
 	} while (ret == -1 && errno == EINTR);
@@ -71,5 +85,5 @@ bool read_tempfile(int fd, std::string *contents)
 		// Can still continue.
 	}
 
-	return true;
+	return ok;
 }
-- 
2.39.2