Re: [Libguestfs] [PATCH v2 2/5] lib: qemu: Factor out common code for reading and writing cache files.
On Tuesday, 12 September 2017 14:29:13 CEST Richard W.M. Jones wrote:
+/**
+ * Generic functions for reading and writing the cache files, used
+ * where we are just reading and writing plain text strings.
+ */
+static int
+generic_read_cache (guestfs_h *g, const char *filename, char **strp)
+{
+ if (access (filename, R_OK) == -1 && errno == ENOENT)
+ return 0; /* no cache, run the test instead */
This will go ahead if access() failed for any other error though;
IMHO a better check could be:
if (access (filename, R_OK) == -1) {
if (errno == ENOENT)
return 0; /* no cache, run the test instead */
perrorf (g, "access: %s", filename);
return -1;
}
+static int
+generic_write_cache (guestfs_h *g, const char *filename, const char *str)
+{
+ CLEANUP_FCLOSE FILE *fp = fopen (filename, "w");
+ if (fp == NULL) {
+ perrorf (g, "%s", filename);
+ return -1;
+ }
+
+ if (fprintf (fp, "%s", str) == -1) {
+ perrorf (g, "%s: write", filename);
+ return -1;
+ }
+
+ return 0;
+}
While this is the same code already used, IMHO it would make more sense
to use open/write directly (since we have a buffer already, it will be
faster than using sprintf); there are snippets that call write() in a
loop until the whole buffer is written in different parts of the
library, so factorizing them could help.
Thanks,
--
Pino Toscano
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