core: support chunked transfer for image files

core/src/main/java/com/cloud/storage/template/HttpTemplateDownloader.java

@@ -27,6 +27,7 @@
 import java.io.RandomAccessFile;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
 
@@ -80,6 +81,18 @@
     private ResourceType resourceType = ResourceType.TEMPLATE;
     private final HttpMethodRetryHandler myretryhandler;
     private boolean followRedirects = false;
+    private boolean isChunkedTransfer;
+
+    protected static final List<String> CUSTOM_HEADERS_FOR_CHUNKED_TRANSFER_SIZE = Arrays.asList(
+            "x-goog-stored-content-length",
+            "x-goog-meta-size",
+            "x-amz-meta-size",
+            "x-amz-meta-content-length",
+            "x-object-meta-size",
+            "x-original-content-length",
+            "x-oss-meta-content-length",
+            "x-file-size");
+    private static final long MIN_FORMAT_VERIFICATION_SIZE = 1024 * 1024;
 
     public HttpTemplateDownloader(StorageLayer storageLayer, String downloadUrl, String toDir, DownloadCompleteCallback callback, long maxTemplateSizeInBytes,
             String user, String password, Proxy proxy, ResourceType resourceType) {
@@ -205,13 +218,11 @@
                  RandomAccessFile out = new RandomAccessFile(file, "rw");
             ) {
                 out.seek(localFileSize);
-
-                logger.info("Starting download from " + downloadUrl + " to " + toFile + " remoteSize=" + toHumanReadableSize(remoteSize) + " , max size=" + toHumanReadableSize(maxTemplateSizeInBytes));
-
-                if (copyBytes(file, in, out)) return 0;
-
+                logger.info("Starting download from {} to {} remoteSize={} , max size={}",downloadUrl, toFile,
+                        toHumanReadableSize(remoteSize), toHumanReadableSize(maxTemplateSizeInBytes));
+                boolean eof = copyBytes(file, in, out);
                 Date finish = new Date();
-                checkDowloadCompletion();
+                checkDownloadCompletion(eof);
                 downloadTime += finish.getTime() - start.getTime();
             } finally { /* in.close() and out.close() */ }
             return totalBytes;
@@ -237,28 +248,32 @@
     }
 
     private boolean copyBytes(File file, InputStream in, RandomAccessFile out) throws IOException {
-        int bytes;
-        byte[] block = new byte[CHUNK_SIZE];
+        byte[] buffer = new byte[CHUNK_SIZE];
         long offset = 0;
-        boolean done = false;
         VerifyFormat verifyFormat = new VerifyFormat(file);
         status = Status.IN_PROGRESS;
-        while (!done && status != Status.ABORTED && offset <= remoteSize) {
-            if ((bytes = in.read(block, 0, CHUNK_SIZE)) > -1) {
-                offset = writeBlock(bytes, out, block, offset);
-                if (!ResourceType.SNAPSHOT.equals(resourceType) &&
-                        !verifyFormat.isVerifiedFormat() &&
-                        (offset >= 1048576 || offset >= remoteSize)) { //let's check format after we get 1MB or full file
-                    verifyFormat.invoke();
-                }
-            } else {
-                done = true;
+        while (status != Status.ABORTED) {
+            int bytesRead = in.read(buffer, 0, CHUNK_SIZE);
+            if (bytesRead == -1) {
+                logger.debug("Reached EOF on input stream");
+                break;
+            }
+            offset = writeBlock(bytesRead, out, buffer, offset);
+            if (!ResourceType.SNAPSHOT.equals(resourceType)
+                    && !verifyFormat.isVerifiedFormat()
+                    && (offset >= MIN_FORMAT_VERIFICATION_SIZE || offset >= remoteSize)) {
+                verifyFormat.invoke();
+            }
+            if (offset >= remoteSize) {
+                logger.debug("Reached expected remote size limit: {} bytes", remoteSize);
+                break;
             }
         }
         out.getFD().sync();
-        return false;
+        return !Status.ABORTED.equals(status);
     }
 
+
     private long writeBlock(int bytes, RandomAccessFile out, byte[] block, long offset) throws IOException {
         out.write(block, 0, bytes);
         offset += bytes;
@@ -267,11 +282,13 @@
         return offset;
     }
 
-    private void checkDowloadCompletion() {
+    private void checkDownloadCompletion(boolean eof) {
         String downloaded = "(incomplete download)";
-        if (totalBytes >= remoteSize) {
+        if (eof && ((totalBytes >= remoteSize) || (isChunkedTransfer && remoteSize == maxTemplateSizeInBytes))) {
             status = Status.DOWNLOAD_FINISHED;
-            downloaded = "(download complete remote=" + toHumanReadableSize(remoteSize) + " bytes)";
+            downloaded = "(download complete remote=" +
+                    (remoteSize == maxTemplateSizeInBytes ? toHumanReadableSize(remoteSize) : "unknown") +
+                    " bytes)";
         }
         errorString = "Downloaded " + toHumanReadableSize(totalBytes) + " bytes " + downloaded;
     }
@@ -293,18 +310,42 @@
         }
     }
 
+    protected long getRemoteSizeForChunkedTransfer() {
+        for (String headerKey : CUSTOM_HEADERS_FOR_CHUNKED_TRANSFER_SIZE) {
+            Header header = request.getResponseHeader(headerKey);
+            if (header == null) {
+                continue;
+            }
+            try {
+                return Long.parseLong(header.getValue());
+            } catch (NumberFormatException ignored) {}
+        }
+        Header contentRangeHeader = request.getResponseHeader("Content-Range");
+        if (contentRangeHeader != null) {
+            String contentRange = contentRangeHeader.getValue();
+            if (contentRange != null && contentRange.contains("/")) {
+                String totalSize = contentRange.substring(contentRange.indexOf('/') + 1).trim();
+                return Long.parseLong(totalSize);
+            }
+        }
+        return 0;
+    }
+
     private boolean tryAndGetRemoteSize() {
         Header contentLengthHeader = request.getResponseHeader("content-length");
-        boolean chunked = false;
+        isChunkedTransfer = false;
         long reportedRemoteSize = 0;
         if (contentLengthHeader == null) {
             Header chunkedHeader = request.getResponseHeader("Transfer-Encoding");
-            if (chunkedHeader == null || !"chunked".equalsIgnoreCase(chunkedHeader.getValue())) {
+            if (chunkedHeader != null && "chunked".equalsIgnoreCase(chunkedHeader.getValue())) {
+                isChunkedTransfer = true;
+                reportedRemoteSize = getRemoteSizeForChunkedTransfer();
+                logger.debug("{} is using chunked transfer encoding, possible remote size: {}", downloadUrl,
+                        reportedRemoteSize);
+            } else {
                 status = Status.UNRECOVERABLE_ERROR;
                 errorString = " Failed to receive length of download ";
                 return false;
-            } else if ("chunked".equalsIgnoreCase(chunkedHeader.getValue())) {
-                chunked = true;
             }
         } else {
             reportedRemoteSize = Long.parseLong(contentLengthHeader.getValue());
@@ -316,9 +357,11 @@
                 return false;
             }
         }
-
         if (remoteSize == 0) {
             remoteSize = reportedRemoteSize;
+            if (remoteSize != 0) {
+                logger.debug("Remote size for {} found to be {}", downloadUrl, toHumanReadableSize(remoteSize));
+            }
         }
         return true;
     }