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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.memory; | |
19 | ||
20 | import java.util.Collection; | |
21 | ||
22 | import org.apache.arrow.memory.rounding.DefaultRoundingPolicy; | |
23 | import org.apache.arrow.memory.rounding.RoundingPolicy; | |
24 | ||
25 | /** | |
26 | * Wrapper class to deal with byte buffer allocation. Ensures users only use designated methods. | |
27 | */ | |
28 | public interface BufferAllocator extends AutoCloseable { | |
29 | ||
30 | /** | |
31 | * Allocate a new or reused buffer of the provided size. Note that the buffer may technically | |
32 | * be larger than the | |
33 | * requested size for rounding purposes. However, the buffer's capacity will be set to the | |
34 | * configured size. | |
35 | * | |
36 | * @param size The size in bytes. | |
37 | * @return a new ArrowBuf, or null if the request can't be satisfied | |
38 | * @throws OutOfMemoryException if buffer cannot be allocated | |
39 | */ | |
40 | ArrowBuf buffer(long size); | |
41 | ||
42 | /** | |
43 | * Allocate a new or reused buffer of the provided size. Note that the buffer may technically | |
44 | * be larger than the | |
45 | * requested size for rounding purposes. However, the buffer's capacity will be set to the | |
46 | * configured size. | |
47 | * | |
48 | * @param size The size in bytes. | |
49 | * @param manager A buffer manager to manage reallocation. | |
50 | * @return a new ArrowBuf, or null if the request can't be satisfied | |
51 | * @throws OutOfMemoryException if buffer cannot be allocated | |
52 | */ | |
53 | ArrowBuf buffer(long size, BufferManager manager); | |
54 | ||
55 | /** | |
56 | * Get the root allocator of this allocator. If this allocator is already a root, return | |
57 | * this directly. | |
58 | * | |
59 | * @return The root allocator | |
60 | */ | |
61 | BufferAllocator getRoot(); | |
62 | ||
63 | /** | |
64 | * Create a new child allocator. | |
65 | * | |
66 | * @param name the name of the allocator. | |
67 | * @param initReservation the initial space reservation (obtained from this allocator) | |
68 | * @param maxAllocation maximum amount of space the new allocator can allocate | |
69 | * @return the new allocator, or null if it can't be created | |
70 | */ | |
71 | BufferAllocator newChildAllocator(String name, long initReservation, long maxAllocation); | |
72 | ||
73 | /** | |
74 | * Create a new child allocator. | |
75 | * | |
76 | * @param name the name of the allocator. | |
77 | * @param listener allocation listener for the newly created child | |
78 | * @param initReservation the initial space reservation (obtained from this allocator) | |
79 | * @param maxAllocation maximum amount of space the new allocator can allocate | |
80 | * @return the new allocator, or null if it can't be created | |
81 | */ | |
82 | BufferAllocator newChildAllocator( | |
83 | String name, | |
84 | AllocationListener listener, | |
85 | long initReservation, | |
86 | long maxAllocation); | |
87 | ||
88 | /** | |
89 | * Close and release all buffers generated from this buffer pool. | |
90 | * | |
91 | * <p>When assertions are on, complains if there are any outstanding buffers; to avoid | |
92 | * that, release all buffers before the allocator is closed.</p> | |
93 | */ | |
94 | @Override | |
95 | void close(); | |
96 | ||
97 | /** | |
98 | * Returns the amount of memory currently allocated from this allocator. | |
99 | * | |
100 | * @return the amount of memory currently allocated | |
101 | */ | |
102 | long getAllocatedMemory(); | |
103 | ||
104 | /** | |
105 | * Return the current maximum limit this allocator imposes. | |
106 | * | |
107 | * @return Limit in number of bytes. | |
108 | */ | |
109 | long getLimit(); | |
110 | ||
111 | /** | |
112 | * Return the initial reservation. | |
113 | * | |
114 | * @return reservation in bytes. | |
115 | */ | |
116 | long getInitReservation(); | |
117 | ||
118 | /** | |
119 | * Set the maximum amount of memory this allocator is allowed to allocate. | |
120 | * | |
121 | * @param newLimit The new Limit to apply to allocations | |
122 | */ | |
123 | void setLimit(long newLimit); | |
124 | ||
125 | /** | |
126 | * Returns the peak amount of memory allocated from this allocator. | |
127 | * | |
128 | * @return the peak amount of memory allocated | |
129 | */ | |
130 | long getPeakMemoryAllocation(); | |
131 | ||
132 | /** | |
133 | * Returns the amount of memory that can probably be allocated at this moment | |
134 | * without exceeding this or any parents allocation maximum. | |
135 | * | |
136 | * @return Headroom in bytes | |
137 | */ | |
138 | long getHeadroom(); | |
139 | ||
140 | /** | |
141 | * Forcibly allocate bytes. Returns whether the allocation fit within limits. | |
142 | * | |
143 | * @param size to increase | |
144 | * @return Whether the allocation fit within limits. | |
145 | */ | |
146 | boolean forceAllocate(long size); | |
147 | ||
148 | ||
149 | /** | |
150 | * Release bytes from this allocator. | |
151 | * | |
152 | * @param size to release | |
153 | */ | |
154 | void releaseBytes(long size); | |
155 | ||
156 | /** | |
157 | * Returns the allocation listener used by this allocator. | |
158 | * | |
159 | * @return the {@link AllocationListener} instance. Or {@link AllocationListener#NOOP} by default if no listener | |
160 | * is configured when this allocator was created. | |
161 | */ | |
162 | AllocationListener getListener(); | |
163 | ||
164 | /** | |
165 | * Returns the parent allocator. | |
166 | * | |
167 | * @return parent allocator | |
168 | */ | |
169 | BufferAllocator getParentAllocator(); | |
170 | ||
171 | /** | |
172 | * Returns the set of child allocators. | |
173 | * | |
174 | * @return set of child allocators | |
175 | */ | |
176 | Collection<BufferAllocator> getChildAllocators(); | |
177 | ||
178 | /** | |
179 | * Create an allocation reservation. A reservation is a way of building up | |
180 | * a request for a buffer whose size is not known in advance. See | |
181 | * | |
182 | * @return the newly created reservation | |
183 | * @see AllocationReservation | |
184 | */ | |
185 | AllocationReservation newReservation(); | |
186 | ||
187 | /** | |
188 | * Get a reference to the empty buffer associated with this allocator. Empty buffers are | |
189 | * special because we don't | |
190 | * worry about them leaking or managing reference counts on them since they don't actually | |
191 | * point to any memory. | |
192 | * | |
193 | * @return the empty buffer | |
194 | */ | |
195 | ArrowBuf getEmpty(); | |
196 | ||
197 | /** | |
198 | * Return the name of this allocator. This is a human readable name that can help debugging. | |
199 | * Typically provides | |
200 | * coordinates about where this allocator was created | |
201 | * | |
202 | * @return the name of the allocator | |
203 | */ | |
204 | String getName(); | |
205 | ||
206 | /** | |
207 | * Return whether or not this allocator (or one if its parents) is over its limits. In the case | |
208 | * that an allocator is | |
209 | * over its limit, all consumers of that allocator should aggressively try to address the | |
210 | * overlimit situation. | |
211 | * | |
212 | * @return whether or not this allocator (or one if its parents) is over its limits | |
213 | */ | |
214 | boolean isOverLimit(); | |
215 | ||
216 | /** | |
217 | * Return a verbose string describing this allocator. If in DEBUG mode, this will also include | |
218 | * relevant stacktraces | |
219 | * and historical logs for underlying objects | |
220 | * | |
221 | * @return A very verbose description of the allocator hierarchy. | |
222 | */ | |
223 | String toVerboseString(); | |
224 | ||
225 | /** | |
226 | * Asserts (using java assertions) that the provided allocator is currently open. If assertions | |
227 | * are disabled, this is | |
228 | * a no-op. | |
229 | */ | |
230 | void assertOpen(); | |
231 | ||
232 | /** | |
233 | * Gets the rounding policy of the allocator. | |
234 | */ | |
235 | default RoundingPolicy getRoundingPolicy() { | |
236 | return DefaultRoundingPolicy.DEFAULT_ROUNDING_POLICY; | |
237 | } | |
238 | } |