feat: Correct ZIP file match when parse.

errnull · errnull · commit f3e204f14e79 · 2019-09-29T20:12:28.000+08:00
diff --git a/Source/SVGAParser.m b/Source/SVGAParser.m
@@ -13,6 +13,8 @@
 #import <SSZipArchive/SSZipArchive.h>
 #import <CommonCrypto/CommonDigest.h>
 
+#define ZIP_MAGIC_NUMBER "PK"
+
 @interface SVGAParser ()
 
 @end
@@ -176,6 +178,14 @@ - (void)clearCache:(nonnull NSString *)cacheKey {
     [[NSFileManager defaultManager] removeItemAtPath:cacheDir error:NULL];
 }
 
++ (BOOL)isZIPData:(NSData *)data {
+    BOOL result = NO;
+    if (!strncmp([data bytes], ZIP_MAGIC_NUMBER, strlen(ZIP_MAGIC_NUMBER))) {
+        result = YES;
+    }
+    return result;
+}
+
 - (void)parseWithData:(nonnull NSData *)data
              cacheKey:(nonnull NSString *)cacheKey
       completionBlock:(void ( ^ _Nullable)(SVGAVideoEntity * _Nonnull videoItem))completionBlock
@@ -192,9 +202,7 @@ - (void)parseWithData:(nonnull NSData *)data
     if (!data || data.length < 4) {
         return;
     }
-    NSData *tag = [data subdataWithRange:NSMakeRange(0, 4)];
-    NSString *fileTagDes = [tag description];
-    if (![fileTagDes containsString:@"504b0304"]) {
+    if (![SVGAParser isZIPData:data]) {
         // Maybe is SVGA 2.0.0
         [parseQueue addOperationWithBlock:^{
             NSData *inflateData = [self zlibInflate:data];
