From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 27 Jan 2012 18:56:36 +0000 (-0800)
Subject: Import: always open and read the file before checking the filename extension
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=bea6637c03a90fbb9e754f5f63625fffb7cbaa69;p=ext%2Fsubsurface.git

Import: always open and read the file before checking the filename extension

Most of the parsers will want the content in memory, so keep them
simple.  The fact that the Suunto parser uses "libzip" that has to
re-open the file is annoying and causes us to re-open the file etc.

But it's the odd man out, so don't design the "open_by_filename()"
function around it.  Pretty much everybody else will want to avoid
having to cook up their own IO routines.

Also, when reading the file, NUL-terminate the buffer.  This allows us
to just treat text files as large strings if we want to, and doesn't
matter for binary files (we still pass in the length explicitly).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/file.c b/file.c
index 192dda6..2e46f94 100644
--- a/file.c
+++ b/file.c
@@ -16,6 +16,7 @@ static int readfile(const char *filename, struct memblock *mem)
 {
 	int ret, fd = open(filename, O_RDONLY);
 	struct stat st;
+	char *buf;
 
 	mem->buffer = NULL;
 	mem->size = 0;
@@ -32,15 +33,17 @@ static int readfile(const char *filename, struct memblock *mem)
 	ret = 0;
 	if (!st.st_size)
 		goto out;
-	mem->buffer = malloc(st.st_size);
+	buf = malloc(st.st_size+1);
 	ret = -1;
 	errno = ENOMEM;
-	if (!mem->buffer)
+	if (!buf)
 		goto out;
+	mem->buffer = buf;
 	mem->size = st.st_size;
-	ret = read(fd, mem->buffer, mem->size);
+	ret = read(fd, buf, mem->size);
 	if (ret < 0)
 		goto free;
+	buf[ret] = 0;
 	if (ret == mem->size)
 		goto out;
 	errno = EIO;
@@ -72,10 +75,11 @@ static void suunto_read(struct zip_file *file, GError **error)
 }
 #endif
 
-static int try_to_open_suunto(const char *filename, GError **error)
+static int try_to_open_suunto(const char *filename, struct memblock *mem, GError **error)
 {
 	int success = 0;
 #ifdef LIBZIP
+	/* Grr. libzip needs to re-open the file, it can't take a buffer */
 	struct zip *zip = zip_open(filename, ZIP_CHECKCONS, NULL);
 
 	if (zip) {
@@ -94,24 +98,28 @@ static int try_to_open_suunto(const char *filename, GError **error)
 	return success;
 }
 
-static int open_by_filename(const char *filename, const char *fmt, GError **error)
+static int open_by_filename(const char *filename, const char *fmt, struct memblock *mem, GError **error)
 {
 	/* Suunto Dive Manager files: SDE */
 	if (!strcasecmp(fmt, "SDE"))
-		return try_to_open_suunto(filename, error);
+		return try_to_open_suunto(filename, mem, error);
 
 	return 0;
 }
 
+static void parse_file_buffer(const char *filename, struct memblock *mem, GError **error)
+{
+	char *fmt = strrchr(filename, '.');
+	if (fmt && open_by_filename(filename, fmt+1, mem, error))
+		return;
+
+	parse_xml_buffer(filename, mem->buffer, mem->size, error);
+}
+
 void parse_file(const char *filename, GError **error)
 {
-	char *fmt;
 	struct memblock mem;
 
-	fmt = strrchr(filename, '.');
-	if (fmt && open_by_filename(filename, fmt+1, error))
-		return;
-
 	if (readfile(filename, &mem) < 0) {
 		fprintf(stderr, "Failed to read '%s'.\n", filename);
 		if (error) {
@@ -123,6 +131,6 @@ void parse_file(const char *filename, GError **error)
 		return;
 	}
 
-	parse_xml_buffer(filename, mem.buffer, mem.size, error);
+	parse_file_buffer(filename, &mem, error);
 	free(mem.buffer);
 }