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1 | /* |
2 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
3 | * contributor license agreements. See the NOTICE file distributed with | |
4 | * this work for additional information regarding copyright ownership. | |
5 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
6 | * (the "License"); you may not use this file except in compliance with | |
7 | * the License. You may obtain a copy of the License at | |
8 | * | |
9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
10 | * | |
11 | * Unless required by applicable law or agreed to in writing, software | |
12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
14 | * See the License for the specific language governing permissions and | |
15 | * limitations under the License. | |
16 | */ | |
17 | ||
18 | package org.apache.arrow.vector.ipc.message; | |
19 | ||
20 | import java.nio.ByteBuffer; | |
21 | ||
22 | import org.apache.arrow.flatbuf.Message; | |
23 | ||
24 | /** | |
25 | * Class to hold resulting Message metadata and buffer containing the serialized Flatbuffer | |
26 | * message when reading messages from a ReadChannel. This handles Message metadata only and | |
27 | * does not include the message body data, which should be subsequently read into an ArrowBuf. | |
28 | */ | |
29 | public class MessageMetadataResult { | |
30 | ||
31 | /** | |
32 | * Construct a container to hold a deserialized Message metadata, and buffer | |
33 | * with the serialized Message as read from a ReadChannel. | |
34 | * | |
35 | * @param messageLength the length of the serialized Flatbuffer message in bytes | |
36 | * @param messageBuffer contains the serialized Flatbuffer Message metadata | |
37 | * @param message the deserialized Flatbuffer Message metadata description | |
38 | */ | |
39 | MessageMetadataResult(int messageLength, ByteBuffer messageBuffer, Message message) { | |
40 | this.messageLength = messageLength; | |
41 | this.messageBuffer = messageBuffer; | |
42 | this.message = message; | |
43 | } | |
44 | ||
45 | /** | |
46 | * Creates a new {@link MessageMetadataResult} by parsing it from the beginning of the buffer. | |
47 | * | |
48 | * @param messageLength The length of the serialized flatbuffer message in bytes (might not be equal to the buffer | |
49 | * size). | |
50 | */ | |
51 | public static MessageMetadataResult create(ByteBuffer buffer, int messageLength) { | |
52 | return new MessageMetadataResult(messageLength, buffer, Message.getRootAsMessage(buffer)); | |
53 | } | |
54 | ||
55 | /** | |
56 | * Get the length of the message metadata in bytes, not including the body length. | |
57 | * | |
58 | * @return number of bytes in the message metadata buffer. | |
59 | */ | |
60 | public int getMessageLength() { | |
61 | return messageLength; | |
62 | } | |
63 | ||
64 | /** | |
65 | * Get the buffer containing the raw message metadata bytes, not including the message body data. | |
66 | * | |
67 | * @return buffer containing the message metadata. | |
68 | */ | |
69 | public ByteBuffer getMessageBuffer() { | |
70 | return messageBuffer; | |
71 | } | |
72 | ||
73 | /** | |
74 | * Returns the bytes remaining in the buffer after parsing the message from it. | |
75 | */ | |
76 | public int bytesAfterMessage() { | |
77 | return message.getByteBuffer().remaining(); | |
78 | } | |
79 | ||
80 | public byte headerType() { | |
81 | return message.headerType(); | |
82 | } | |
83 | ||
84 | /** | |
85 | * Check if the message is followed by a body. This will be true if the message has a body | |
86 | * length > 0, which indicates that a message body needs to be read from the input source. | |
87 | * | |
88 | * @return true if message has a defined body | |
89 | */ | |
90 | public boolean messageHasBody() { | |
91 | return message.bodyLength() > 0; | |
92 | } | |
93 | ||
94 | /** | |
95 | * Get the length of the message body. | |
96 | * | |
97 | * @return number of bytes of the message body | |
98 | */ | |
99 | public long getMessageBodyLength() { | |
100 | return message.bodyLength(); | |
101 | } | |
102 | ||
103 | /** | |
104 | * Get the realized flatbuf Message metadata description. | |
105 | * | |
106 | * @return Message metadata | |
107 | */ | |
108 | public Message getMessage() { | |
109 | return message; | |
110 | } | |
111 | ||
112 | private final int messageLength; | |
113 | private final ByteBuffer messageBuffer; | |
114 | private final Message message; | |
115 | } |