reduce getArchiveComment store requests

Author: brokkoli71

src/main/java/dev/zarr/zarrjava/store/FilesystemStore.java

@@ -177,6 +177,8 @@ public InputStream getInputStream(String[] keys, long start, long end) {
     public long getSize(String[] keys) {
         try {
             return Files.size(resolveKeys(keys));
+        } catch (NoSuchFileException e) {
+            return -1;
         } catch (IOException e) {
             throw new RuntimeException(e);
         }

src/main/java/dev/zarr/zarrjava/store/HttpStore.java

@@ -148,7 +148,7 @@ public long getSize(String[] keys) {
         try {
             Response response = call.execute();
             if (!response.isSuccessful()) {
-                throw new IOException("Failed to get size: " + response.code());
+                return -1;
             }
 
             String contentLength = response.header("Content-Length");

src/main/java/dev/zarr/zarrjava/store/MemoryStore.java

@@ -98,7 +98,7 @@ public InputStream getInputStream(String[] keys, long start, long end) {
     public long getSize(String[] keys) {
         byte[] bytes = map.get(resolveKeys(keys));
         if (bytes == null) {
-            throw new RuntimeException(new java.io.FileNotFoundException("Key not found: " + String.join("/", keys)));
+            return -1;
         }
         return bytes.length;
     }

src/main/java/dev/zarr/zarrjava/store/ReadOnlyZipStore.java

@@ -213,7 +213,7 @@ public long getSize(String[] keys) {
                 }
                 return size;
             }
-            throw new RuntimeException(new java.io.FileNotFoundException("Key not found: " + resolveKeys(keys)));
+            return -1; // file not found
         } catch (IOException e) {
             throw new RuntimeException(e);
         }

src/main/java/dev/zarr/zarrjava/store/S3Store.java

@@ -141,7 +141,7 @@ public long getSize(String[] keys) {
     try {
       return s3client.headObject(req).contentLength();
     } catch (NoSuchKeyException e) {
-      throw new RuntimeException(e);
+        return -1;
     }
   }
 

src/main/java/dev/zarr/zarrjava/store/Store.java

@@ -50,5 +50,11 @@ default InputStream getInputStream(String[] keys) {
     return getInputStream(keys, 0, -1);
   }
 
+/**
+ * Gets the size in bytes of the data stored at the given keys.
+ *
+ * @param keys The keys identifying the data.
+ * @return The size in bytes of the data stored at the given keys. -1 if the keys do not exist.
+  */
   long getSize(String[] keys);
 }

src/main/java/dev/zarr/zarrjava/store/ZipStore.java

@@ -16,14 +16,14 @@ public String getArchiveComment() throws IOException {
         // Attempt to read from the end of the file to find the EOCD record.
         // We try a small chunk first (1KB) which covers most short comments (or no comment),
         // then the maximum possible EOCD size (approx 65KB).
-        if (!underlyingStore.exists()) {
+        long fileSize = underlyingStore.getSize();
+        if (fileSize < 22) {
             return null;
         }
         int[] readSizes = {1024, 65535 + 22};
 
         for (int size : readSizes) {
             ByteBuffer buffer;
-            long fileSize = underlyingStore.getSize();
 
             if (fileSize < size){
                 buffer = underlyingStore.read();
@@ -48,6 +48,9 @@ public String getArchiveComment() throws IOException {
             if (comment != null) {
                 return comment;
             }
+            if (fileSize < size){
+                break;
+            }
         }
         return null;
     }