Move cache validation logic into ctpv.c

Makefile

@@ -8,7 +8,7 @@ PRE := $(wildcard prev/*.sh)
 GEN := gen/prev/scripts.h gen/server.h
 
 CFLAGS  += -Os -MD -Wall -Wextra -Wno-unused-parameter
-LDFLAGS += -lmagic
+LDFLAGS += -lmagic -lcrypto
 
 all: ctpv
 

ctpv.c

@@ -5,6 +5,7 @@
 #include <signal.h>
 #include <unistd.h>
 #include <sys/stat.h>
+#include <openssl/md5.h>
 
 #include "error.h"
 #include "server.h"
@@ -25,9 +26,11 @@ static struct {
         MODE_END,
         MODE_LIST,
         MODE_MIME,
-        MODE_NEWER,
+        MODE_CHECK_CACHE,
     } mode;
     char *server_id_s;
+    char *check_file;
+    char *ctpv_path;
 } ctpv = { .mode = MODE_PREVIEW };
 
 static void cleanup(void) {
@@ -98,6 +101,11 @@ static int check_file(char const *f)
 
 static int preview(int argc, char *argv[])
 {
+    if (!ctpv.ctpv_path) {
+        print_error("argument 0 is null");
+        return ERR;
+    }
+
     char *f, *w, *h, *x, *y;
     GET_PARG(f, 0);
     GET_PARG(w, 1);
@@ -114,7 +122,10 @@ static int preview(int argc, char *argv[])
     const char *mimetype;
     ERRCHK_RET(!(mimetype = get_mimetype(f)));
 
-    PreviewArgs args = { .f = f, .w = w, .h = h, .x = x, .y = y };
+    PreviewArgs args = {
+        .ctpv = ctpv.ctpv_path,
+        .f = f, .w = w, .h = h, .x = x, .y = y
+    };
 
     return run_preview(get_ext(f), mimetype, &args);
 }
@@ -190,17 +201,8 @@ static int mime(int argc, char *argv[])
     return OK;
 }
 
-static int newer(int argc, char *argv[])
+static int is_newer(char *f1, char *f2)
 {
-    char *f1, *f2;
-    GET_PARG(f1, 0);
-    GET_PARG(f2, 1);
-
-    if (!f1 || !f2) {
-        print_error("2 file should be given");
-        return ERR;
-    }
-
     struct stat stat1, stat2;
     ERRCHK_RET(stat(f1, &stat1) == -1, FUNCFAILED("stat"), ERRNOS);
     ERRCHK_RET(stat(f2, &stat2) == -1, FUNCFAILED("stat"), ERRNOS);
@@ -214,12 +216,54 @@ static int newer(int argc, char *argv[])
     return OK;
 }
 
+static void md5_string(char *buf, size_t len, char *s)
+{
+    unsigned char out[MD5_DIGEST_LENGTH];
+    char b[16];
+
+    MD5((const unsigned char *)s, strlen(s), out);
+
+    buf[0] = '\0';
+    for(unsigned int i = 0; i < LEN(out); i++) {
+        snprintf(b, LEN(b)-1, "%02x", out[i]);
+        strncat(buf, b, len);
+    }
+}
+
+static int check_cache(void)
+{
+    ERRCHK_RET_OK(check_file(ctpv.check_file));
+
+    char cache_file[FILENAME_MAX];
+    ERRCHK_RET_OK(
+        get_cache_dir(cache_file, LEN(cache_file) - 1, "ctpv//"));
+
+    {
+        char cache_file_cpy[FILENAME_MAX];
+        strncpy(cache_file_cpy, cache_file, LEN(cache_file_cpy) - 1);
+        ERRCHK_RET(mkpath(cache_file_cpy, 0700) == -1, FUNCFAILED("mkpath"),
+                   ERRNOS);
+    }
+
+    char name[64];
+    md5_string(name, LEN(name)-1, ctpv.check_file);
+
+    strncat(cache_file, name, LEN(cache_file)-1);
+    puts(cache_file);
+
+    if (access(cache_file, F_OK) != 0)
+        return ERR;
+
+    return is_newer(cache_file, ctpv.check_file);
+}
+
 int main(int argc, char *argv[])
 {
-    program = argc > 0 ? argv[0] : "ctpv";
+    ctpv.ctpv_path = argc > 0 ? argv[0] : NULL;
+    program = ctpv.ctpv_path ? ctpv.ctpv_path : "ctpv";
 
     int c;
-    while ((c = getopt(argc, argv, "s:ce:lmn")) != -1) {
+    while ((c = getopt(argc, argv, "s:ce:lmC:")) != -1) {
         switch (c) {
         case 's':
             ctpv.mode = MODE_SERVER;
@@ -238,8 +282,9 @@ int main(int argc, char *argv[])
         case 'm':
             ctpv.mode = MODE_MIME;
             break;
-        case 'n':
-            ctpv.mode = MODE_NEWER;
+        case 'C':
+            ctpv.mode = MODE_CHECK_CACHE;
+            ctpv.check_file = optarg;
             break;
         default:
             return EXIT_FAILURE;
@@ -269,8 +314,8 @@ int main(int argc, char *argv[])
         case MODE_MIME:
             ret = mime(argc, argv);
             break;
-        case MODE_NEWER:
-            ret = newer(argc, argv);
+        case MODE_CHECK_CACHE:
+            ret = check_cache();
             break;
         default:
             PRINTINTERR("unknowm mode: %d", ctpv.mode);

helpers.sh

@@ -20,11 +20,7 @@ check_exist() {
 }
 
 cache() {
-	cache_d="${XDG_CACHE_HOME:-$HOME/.cache}/ctpv"
-	mkdir -p "$cache_d"
-	cache_f="$cache_d/$(printf '%s' "$f" | md5sum - | cut -d' ' -f1)"
-	test -e "$cache_f" || return
-	ctpv -n "$cache_f" "$f"
+	cache_f="$("$ctpv" -C "$f")"
 }
 
 show_image() {

preview.c

@@ -155,6 +155,7 @@ static int run(Preview *p, int *exitcode)
 
 int run_preview(const char *ext, const char *mimetype, PreviewArgs *pa)
 {
+    SET_PENV("ctpv", pa->ctpv);
     SET_PENV("f", pa->f);
     SET_PENV("w", pa->w);
     SET_PENV("h", pa->h);

preview.h

@@ -9,7 +9,7 @@ typedef struct {
 } Preview;
 
 typedef struct {
-    char *f, *w, *h, *x, *y;
+    char *ctpv, *f, *w, *h, *x, *y;
 } PreviewArgs;
 
 void init_previews(Preview *ps, size_t len);

utils.c

@@ -1,12 +1,14 @@
-#include <sys/wait.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
 
 #include "error.h"
 #include "utils.h"
 
-char *program;
+char *program = NULL;
 
 int spawn_redirect(const void *arg)
 {
@@ -80,6 +82,40 @@ int strcmpnull(char const *s1, char const *s2)
     return strcmp(s1, s2);
 }
 
+int get_cache_dir(char *buf, size_t len, char *name)
+{
+    char *home, *cache_d, cache_d_buf[FILENAME_MAX];
+
+    if (!(cache_d = getenv("XDG_CACHE_HOME"))) {
+        home = getenv("HOME");
+        ERRCHK_RET(!home, "HOME env var does not exist");
+
+        snprintf(cache_d_buf, LEN(cache_d_buf)-1, "%s/.cache", home);
+        cache_d = cache_d_buf;
+    }
+
+    snprintf(buf, len, "%s/%s", cache_d, name);
+    return OK;
+}
+
+int mkpath(char* file_path, mode_t mode)
+{
+    for (char* p = strchr(file_path + 1, '/'); p; p = strchr(p + 1, '/')) {
+        *p = '\0';
+
+        if (mkdir(file_path, mode) == -1) {
+            if (errno != EEXIST) {
+                *p = '/';
+                return -1;
+            }
+        }
+
+        *p = '/';
+    }
+
+    return 0;
+}
+
 CharVec char_v_new(size_t cap)
 {
     CharVec v;

utils.h

@@ -34,6 +34,8 @@ int spawn(char *args[], pid_t *cpid, int *exitcode, int (*cfunc)(const void *),
           const void *carg);
 
 int strcmpnull(char const *s1, char const *s2);
+int get_cache_dir(char *buf, size_t len, char *name);
+int mkpath(char* file_path, mode_t mode);
 
 CharVec char_v_new(size_t cap);
 void char_v_append(CharVec *v, char c);