Github user jvwing commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1482#discussion_r100469488
--- Diff:
nifi-nar-bundles/nifi-gcp-bundle/nifi-gcp-processors/src/main/java/org/apache/nifi/processors/gcp/storage/FetchGCSObject.java
---
@@ -0,0 +1,340 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.nifi.processors.gcp.storage;
+
+import com.google.cloud.ReadChannel;
+import com.google.cloud.storage.Acl;
+import com.google.cloud.storage.Blob;
+import com.google.cloud.storage.BlobId;
+import com.google.cloud.storage.BlobInfo;
+import com.google.cloud.storage.Storage;
+import com.google.cloud.storage.StorageException;
+import com.google.common.collect.ImmutableList;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.WritesAttribute;
+import org.apache.nifi.annotation.behavior.WritesAttributes;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.SeeAlso;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.flowfile.attributes.CoreAttributes;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.exception.ProcessException;
+import org.apache.nifi.processor.util.StandardValidators;
+
+import java.nio.channels.Channels;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.BUCKET_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.BUCKET_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CACHE_CONTROL_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CACHE_CONTROL_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.COMPONENT_COUNT_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.COMPONENT_COUNT_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_DISPOSITION_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_DISPOSITION_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_ENCODING_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_ENCODING_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_LANGUAGE_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_LANGUAGE_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_TYPE_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CONTENT_TYPE_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CRC32C_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CRC32C_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CREATE_TIME_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.CREATE_TIME_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.ENCRYPTION_ALGORITHM_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.ENCRYPTION_ALGORITHM_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.ENCRYPTION_SHA256_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.ENCRYPTION_SHA256_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.ETAG_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.ETAG_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.GENERATED_ID_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.GENERATED_ID_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.GENERATION_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.GENERATION_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.KEY_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.KEY_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.MD5_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.MD5_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.MEDIA_LINK_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.MEDIA_LINK_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.METAGENERATION_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.METAGENERATION_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.OWNER_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.OWNER_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.OWNER_TYPE_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.OWNER_TYPE_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.SIZE_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.SIZE_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.UPDATE_TIME_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.UPDATE_TIME_DESC;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.URI_ATTR;
+import static
org.apache.nifi.processors.gcp.storage.StorageAttributes.URI_DESC;
+
+@InputRequirement(InputRequirement.Requirement.INPUT_REQUIRED)
+@Tags({"google cloud", "google", "storage", "gcs", "fetch"})
+@CapabilityDescription("Fetches a file from a Google Cloud Bucket.
Designed to be used in tandem with ListGCSBucket.")
+@SeeAlso({ListGCSBucket.class, PutGCSObject.class, DeleteGCSObject.class})
+@WritesAttributes({
+ @WritesAttribute(attribute = "filename", description = "The name
of the file, parsed if possible from the " +
+ "Content-Disposition response header"),
+ @WritesAttribute(attribute = BUCKET_ATTR, description =
BUCKET_DESC),
+ @WritesAttribute(attribute = KEY_ATTR, description = KEY_DESC),
+ @WritesAttribute(attribute = SIZE_ATTR, description = SIZE_DESC),
+ @WritesAttribute(attribute = CACHE_CONTROL_ATTR, description =
CACHE_CONTROL_DESC),
+ @WritesAttribute(attribute = COMPONENT_COUNT_ATTR, description =
COMPONENT_COUNT_DESC),
+ @WritesAttribute(attribute = CONTENT_DISPOSITION_ATTR, description
= CONTENT_DISPOSITION_DESC),
+ @WritesAttribute(attribute = CONTENT_ENCODING_ATTR, description =
CONTENT_ENCODING_DESC),
+ @WritesAttribute(attribute = CONTENT_LANGUAGE_ATTR, description =
CONTENT_LANGUAGE_DESC),
+ @WritesAttribute(attribute = CONTENT_TYPE_ATTR, description =
CONTENT_TYPE_DESC),
+ @WritesAttribute(attribute = CRC32C_ATTR, description =
CRC32C_DESC),
+ @WritesAttribute(attribute = CREATE_TIME_ATTR, description =
CREATE_TIME_DESC),
+ @WritesAttribute(attribute = UPDATE_TIME_ATTR, description =
UPDATE_TIME_DESC),
+ @WritesAttribute(attribute = ENCRYPTION_ALGORITHM_ATTR,
description = ENCRYPTION_ALGORITHM_DESC),
+ @WritesAttribute(attribute = ENCRYPTION_SHA256_ATTR, description =
ENCRYPTION_SHA256_DESC),
+ @WritesAttribute(attribute = ETAG_ATTR, description = ETAG_DESC),
+ @WritesAttribute(attribute = GENERATED_ID_ATTR, description =
GENERATED_ID_DESC),
+ @WritesAttribute(attribute = GENERATION_ATTR, description =
GENERATION_DESC),
+ @WritesAttribute(attribute = MD5_ATTR, description = MD5_DESC),
+ @WritesAttribute(attribute = MEDIA_LINK_ATTR, description =
MEDIA_LINK_DESC),
+ @WritesAttribute(attribute = METAGENERATION_ATTR, description =
METAGENERATION_DESC),
+ @WritesAttribute(attribute = OWNER_ATTR, description = OWNER_DESC),
+ @WritesAttribute(attribute = OWNER_TYPE_ATTR, description =
OWNER_TYPE_DESC),
+ @WritesAttribute(attribute = URI_ATTR, description = URI_DESC)
+})
+public class FetchGCSObject extends AbstractGCSProcessor {
+ public static final PropertyDescriptor KEY = new PropertyDescriptor
+ .Builder().name("gcs-key")
+ .displayName("Key")
+ .description(KEY_DESC)
+ .required(true)
+ .defaultValue("${" + CoreAttributes.FILENAME.key() + "}")
+ .expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .build();
+
+ public static final PropertyDescriptor GENERATION = new
PropertyDescriptor.Builder()
+ .name("gcs-generation")
+ .displayName("Object Generation")
+ .description("The generation of the Object to download. If
null, will download latest generation.")
+ .expressionLanguageSupported(true)
+ .addValidator(StandardValidators.POSITIVE_LONG_VALIDATOR)
+ .required(false)
+ .build();
+
+ public static final PropertyDescriptor ENCRYPTION_KEY = new
PropertyDescriptor.Builder()
+ .name("gcs-server-side-encryption-key")
+ .displayName("Server Side Encryption Key")
+ .description("An AES256 Key (encoded in base64) which the
object has been encrypted in.")
+ .required(false)
+ .expressionLanguageSupported(true)
+ .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+ .sensitive(true)
+ .build();
+
+ @Override
+ public List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+ return ImmutableList.<PropertyDescriptor>builder()
+ .addAll(super.getSupportedPropertyDescriptors())
+ .add(KEY)
+ .add(GENERATION)
+ .add(ENCRYPTION_KEY)
+ .build();
+ }
+
+
+
+ @Override
+ public void onTrigger(ProcessContext context, ProcessSession session)
throws ProcessException {
+ FlowFile flowFile = session.get();
+ if (flowFile == null) {
+ return;
+ }
+
+ final long startNanos = System.nanoTime();
+
+ String bucketName = context.getProperty(BUCKET)
+ .evaluateAttributeExpressions(flowFile)
+ .getValue();
+ String key = context.getProperty(KEY)
+ .evaluateAttributeExpressions(flowFile)
+ .getValue();
+ Long generation = context.getProperty(GENERATION)
+ .evaluateAttributeExpressions(flowFile)
+ .asLong();
+ String encryptionKey = context.getProperty(ENCRYPTION_KEY)
+ .evaluateAttributeExpressions(flowFile)
+ .getValue();
+
+ final Storage storage = getCloudService();
+ final Map<String, String> attributes = new HashMap<>();
+ final BlobId blobId = BlobId.of(bucketName, key, generation);
+
+ try {
+ final List<Storage.BlobSourceOption> blobSourceOptions = new
ArrayList<>(2);
+
+ if (encryptionKey != null) {
+
blobSourceOptions.add(Storage.BlobSourceOption.decryptionKey(encryptionKey));
+ }
+
+ if (generation != null) {
+
blobSourceOptions.add(Storage.BlobSourceOption.generationMatch());
+ }
+
+ final Blob blob = storage.get(blobId);
+
+ if (blob == null) {
+ throw new StorageException(404, "Blob " + blobId + " not
found");
+ }
+
+ final ReadChannel reader = storage.reader(blobId,
blobSourceOptions.toArray(new
Storage.BlobSourceOption[blobSourceOptions.size()]));
+
+ //TODO: Implement state checkpoints / ability to restore for
long blob reads
--- End diff --
I don't recommend the TODO comments. They won't mean the same thing to
other devs they mean to you, and might confuse people about what's working or
not. They do exist in the NiFi codebase, however, I don't think there's a hard
rule against it. Also, you can create a JIRA for the large blob feature.
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