Use version-specific cache location.

Move the cache location to a subdirectory within Scrap and encode
the cache version in the filename.

This allows software using different versions of RUfl to coexist
on the same system without trying to share the same cache (and
thus rescanning fonts every time).

1 files changed, 52 insertions, 8 deletions

diff --git a/src/rufl_init.c b/src/rufl_init.c
index 25753d6..6ec21b7 100644
--- a/src/rufl_init.c
+++ b/src/rufl_init.c
@@ -14,6 +14,8 @@
 #include <string.h>
 #include <strings.h>
 #include <search.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <oslib/font.h>
 #include <oslib/hourglass.h>
 #include <oslib/os.h>
@@ -1329,6 +1331,52 @@ int rufl_unicode_map_cmp(const void *z1, const void *z2)
 }
 
 
+static FILE *rufl_open_cache(const char *mode)
+{
+	const unsigned int version = rufl_CACHE_VERSION;
+	size_t len;
+	FILE *fp;
+	char fn[PATH_MAX];
+
+	if (!mode)
+		return NULL;
+
+	strcpy(fn, rufl_CACHE_TEMPLATE);
+	len = strlen(fn);
+
+	/* Fill in version suffix */
+	fn[len-4] = "0123456789abcdef"[(version>>12) & 0xf];
+	fn[len-3] = "0123456789abcdef"[(version>> 8) & 0xf];
+	fn[len-2] = "0123456789abcdef"[(version>> 4) & 0xf];
+	fn[len-1] = "0123456789abcdef"[version & 0xf];
+
+	if (mode[0] == 'a' || mode[0] == 'w') {
+		/* Wind back to directory separator */
+		while (len > 0 && fn[len] != '.')
+			len--;
+		if (len == 0) {
+			LOG("%s", "Malformed cache location");
+			return NULL;
+		}
+
+		/* Ensure directory exists */
+		fn[len] = '\0';
+		if (mkdir(fn, 0755) == -1 && errno != EEXIST) {
+			LOG("mkdir: 0x%x: %s", errno, strerror(errno));
+			return NULL;
+		}
+		fn[len] = '.';
+	}
+
+	fp = fopen(fn, mode);
+	if (!fp) {
+		LOG("fopen: 0x%x: %s", errno, strerror(errno));
+		return NULL;;
+	}
+
+	return fp;
+}
+
 /**
  * Save character sets to cache.
  */
@@ -1340,11 +1388,9 @@ rufl_code rufl_save_cache(void)
 	size_t len;
 	FILE *fp;
 
-	fp = fopen(rufl_CACHE, "wb");
-	if (!fp) {
-		LOG("fopen: 0x%x: %s", errno, strerror(errno));
+	fp = rufl_open_cache("wb");
+	if (!fp)
 		return rufl_OK;
-	}
 
 	/* cache format version */
 	if (fwrite(&version, sizeof version, 1, fp) != 1) {
@@ -1494,11 +1540,9 @@ rufl_code rufl_load_cache(void)
 	struct rufl_unicode_map *umap = NULL;
 	unsigned int num_umaps = 0;
 
-	fp = fopen(rufl_CACHE, "rb");
-	if (!fp) {
-		LOG("fopen: 0x%x: %s", errno, strerror(errno));
+	fp = rufl_open_cache("rb");
+	if (!fp)
 		return rufl_OK;
-	}
 
 	/* cache format version */
 	if (fread(&version, sizeof version, 1, fp) != 1) {