Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Browse files
Browse the repository at this point in the history
feat: Implementation of Firestore Bundle Builder (#293)
- Loading branch information
Showing
9 changed files
with
809 additions
and
45 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
232 changes: 232 additions & 0 deletions
232
google-cloud-firestore/src/main/java/com/google/cloud/firestore/FirestoreBundle.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,232 @@ | ||
/* | ||
* Copyright 2020 Google LLC | ||
* | ||
* Licensed 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 com.google.cloud.firestore; | ||
|
||
import com.google.cloud.Timestamp; | ||
import com.google.common.base.Optional; | ||
import com.google.common.collect.Lists; | ||
import com.google.firestore.bundle.BundleElement; | ||
import com.google.firestore.bundle.BundleMetadata; | ||
import com.google.firestore.bundle.BundledDocumentMetadata; | ||
import com.google.firestore.bundle.BundledQuery; | ||
import com.google.firestore.bundle.NamedQuery; | ||
import com.google.firestore.v1.Document; | ||
import com.google.protobuf.InvalidProtocolBufferException; | ||
import com.google.protobuf.util.JsonFormat; | ||
import java.nio.ByteBuffer; | ||
import java.nio.charset.StandardCharsets; | ||
import java.util.HashMap; | ||
import java.util.List; | ||
import java.util.Map; | ||
|
||
/** Represents a Firestore data bundle with results from the given document and query snapshots. */ | ||
public final class FirestoreBundle { | ||
|
||
static final int BUNDLE_SCHEMA_VERSION = 1; | ||
// Printer to encode protobuf objects into JSON string. | ||
private static final JsonFormat.Printer PRINTER = JsonFormat.printer(); | ||
|
||
// Raw byte array to hold the content of the bundle. | ||
private byte[] bundleData; | ||
|
||
/** Builds a Firestore data bundle with results from the given document and query snapshots. */ | ||
public static final class Builder { | ||
// Id of the bundle. | ||
private String id; | ||
// Resulting documents for the bundle, keyed by full document path. | ||
private Map<String, BundledDocument> documents = new HashMap<>(); | ||
// Named queries saved in the bundle, keyed by query name. | ||
private Map<String, NamedQuery> namedQueries = new HashMap<>(); | ||
// The latest read time among all bundled documents and queries. | ||
private Timestamp latestReadTime = Timestamp.MIN_VALUE; | ||
|
||
public Builder(String id) { | ||
this.id = id; | ||
} | ||
|
||
/** | ||
* Adds a Firestore document snapshot to the bundle. Both the documents data and the document | ||
* read time will be included in the bundle. | ||
* | ||
* @param documentSnapshot A document snapshot to add. | ||
* @returns This instance. | ||
*/ | ||
public Builder add(DocumentSnapshot documentSnapshot) { | ||
return add(documentSnapshot, Optional.<String>absent()); | ||
} | ||
|
||
private Builder add(DocumentSnapshot documentSnapshot, Optional<String> queryName) { | ||
String documentName = documentSnapshot.getReference().getName(); | ||
BundledDocument originalDocument = documents.get(documentSnapshot.getReference().getName()); | ||
List<String> queries = | ||
originalDocument == null | ||
? Lists.<String>newArrayList() | ||
: Lists.newArrayList(originalDocument.getMetadata().getQueriesList()); | ||
|
||
// Update with document built from `documentSnapshot` because it is newer. | ||
Timestamp snapReadTime = | ||
documentSnapshot.getReadTime() == null | ||
? Timestamp.MIN_VALUE | ||
: documentSnapshot.getReadTime(); | ||
if (originalDocument == null | ||
|| originalDocument.getMetadata().getReadTime() == null | ||
|| snapReadTime.compareTo( | ||
Timestamp.fromProto(originalDocument.getMetadata().getReadTime())) | ||
> 0) { | ||
BundledDocumentMetadata metadata = | ||
BundledDocumentMetadata.newBuilder() | ||
.setName(documentName) | ||
.setReadTime(snapReadTime.toProto()) | ||
.setExists(documentSnapshot.exists()) | ||
.build(); | ||
Document document = | ||
documentSnapshot.exists() ? documentSnapshot.toDocumentPb().build() : null; | ||
documents.put(documentName, new BundledDocument(metadata, document)); | ||
} | ||
|
||
// Update queries to include all queries whose results include this document. | ||
if (queryName.isPresent()) { | ||
queries.add(queryName.get()); | ||
} | ||
documents | ||
.get(documentName) | ||
.setMetadata( | ||
documents | ||
.get(documentName) | ||
.getMetadata() | ||
.toBuilder() | ||
.clearQueries() | ||
.addAllQueries(queries) | ||
.build()); | ||
|
||
if (documentSnapshot.getReadTime().compareTo(latestReadTime) > 0) { | ||
latestReadTime = documentSnapshot.getReadTime(); | ||
} | ||
|
||
return this; | ||
} | ||
|
||
/** | ||
* Adds a Firestore query snapshots to the bundle. Both the documents in the query snapshots and | ||
* the query read time will be included in the bundle. | ||
* | ||
* @param queryName The name of the query to add. | ||
* @param querySnap The query snapshot to add. | ||
* @returns This instance. | ||
*/ | ||
public Builder add(String queryName, QuerySnapshot querySnap) { | ||
BundledQuery query = querySnap.getQuery().toBundledQuery(); | ||
NamedQuery namedQuery = | ||
NamedQuery.newBuilder() | ||
.setName(queryName) | ||
.setReadTime(querySnap.getReadTime().toProto()) | ||
.setBundledQuery(query) | ||
.build(); | ||
namedQueries.put(queryName, namedQuery); | ||
|
||
for (QueryDocumentSnapshot snapshot : querySnap.getDocuments()) { | ||
add(snapshot, Optional.of(queryName)); | ||
} | ||
|
||
if (querySnap.getReadTime().compareTo(latestReadTime) > 0) { | ||
latestReadTime = querySnap.getReadTime(); | ||
} | ||
|
||
return this; | ||
} | ||
|
||
public FirestoreBundle build() { | ||
StringBuilder buffer = new StringBuilder(); | ||
|
||
for (NamedQuery namedQuery : namedQueries.values()) { | ||
buffer.append( | ||
elementToLengthPrefixedStringBuilder( | ||
BundleElement.newBuilder().setNamedQuery(namedQuery).build())); | ||
} | ||
|
||
for (BundledDocument bundledDocument : documents.values()) { | ||
buffer.append( | ||
elementToLengthPrefixedStringBuilder( | ||
BundleElement.newBuilder() | ||
.setDocumentMetadata(bundledDocument.getMetadata()) | ||
.build())); | ||
if (bundledDocument.getDocument() != null) { | ||
buffer.append( | ||
elementToLengthPrefixedStringBuilder( | ||
BundleElement.newBuilder().setDocument(bundledDocument.getDocument()).build())); | ||
} | ||
} | ||
|
||
BundleMetadata metadata = | ||
BundleMetadata.newBuilder() | ||
.setId(id) | ||
.setCreateTime(latestReadTime.toProto()) | ||
.setVersion(BUNDLE_SCHEMA_VERSION) | ||
.setTotalDocuments(documents.size()) | ||
.setTotalBytes(buffer.toString().getBytes().length) | ||
.build(); | ||
BundleElement element = BundleElement.newBuilder().setMetadata(metadata).build(); | ||
buffer.insert(0, elementToLengthPrefixedStringBuilder(element)); | ||
|
||
return new FirestoreBundle(buffer.toString().getBytes(StandardCharsets.UTF_8)); | ||
} | ||
|
||
private StringBuilder elementToLengthPrefixedStringBuilder(BundleElement element) { | ||
String elementJson = null; | ||
try { | ||
elementJson = PRINTER.print(element); | ||
} catch (InvalidProtocolBufferException e) { | ||
throw new RuntimeException(e); | ||
} | ||
return new StringBuilder().append(elementJson.getBytes().length).append(elementJson); | ||
} | ||
} | ||
|
||
private FirestoreBundle(byte[] data) { | ||
bundleData = data; | ||
} | ||
|
||
/** Returns the bundle content as a readonly {@link ByteBuffer}. */ | ||
public ByteBuffer toByteBuffer() { | ||
return ByteBuffer.wrap(bundleData).asReadOnlyBuffer(); | ||
} | ||
|
||
/** | ||
* Convenient class to hold both the metadata and the actual content of a document to be bundled. | ||
*/ | ||
private static class BundledDocument { | ||
private BundledDocumentMetadata metadata; | ||
private final Document document; | ||
|
||
BundledDocument(BundledDocumentMetadata metadata, Document document) { | ||
this.metadata = metadata; | ||
this.document = document; | ||
} | ||
|
||
public BundledDocumentMetadata getMetadata() { | ||
return metadata; | ||
} | ||
|
||
void setMetadata(BundledDocumentMetadata metadata) { | ||
this.metadata = metadata; | ||
} | ||
|
||
public Document getDocument() { | ||
return document; | ||
} | ||
} | ||
} |
Oops, something went wrong.