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.