1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/thirdparty/com/squareup/picasso/MarkableInputStream.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,157 @@
1.4 +/*
1.5 + * Copyright (C) 2013 Square, Inc.
1.6 + *
1.7 + * Licensed under the Apache License, Version 2.0 (the "License");
1.8 + * you may not use this file except in compliance with the License.
1.9 + * You may obtain a copy of the License at
1.10 + *
1.11 + * http://www.apache.org/licenses/LICENSE-2.0
1.12 + *
1.13 + * Unless required by applicable law or agreed to in writing, software
1.14 + * distributed under the License is distributed on an "AS IS" BASIS,
1.15 + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
1.16 + * See the License for the specific language governing permissions and
1.17 + * limitations under the License.
1.18 + */
1.19 +package com.squareup.picasso;
1.20 +
1.21 +import java.io.BufferedInputStream;
1.22 +import java.io.IOException;
1.23 +import java.io.InputStream;
1.24 +
1.25 +/**
1.26 + * An input stream wrapper that supports unlimited independent cursors for
1.27 + * marking and resetting. Each cursor is a token, and it's the caller's
1.28 + * responsibility to keep track of these.
1.29 + */
1.30 +final class MarkableInputStream extends InputStream {
1.31 + private final InputStream in;
1.32 +
1.33 + private long offset;
1.34 + private long reset;
1.35 + private long limit;
1.36 +
1.37 + private long defaultMark = -1;
1.38 +
1.39 + public MarkableInputStream(InputStream in) {
1.40 + if (!in.markSupported()) {
1.41 + in = new BufferedInputStream(in);
1.42 + }
1.43 + this.in = in;
1.44 + }
1.45 +
1.46 + /** Marks this place in the stream so we can reset back to it later. */
1.47 + @Override public void mark(int readLimit) {
1.48 + defaultMark = savePosition(readLimit);
1.49 + }
1.50 +
1.51 + /**
1.52 + * Returns an opaque token representing the current position in the stream.
1.53 + * Call {@link #reset(long)} to return to this position in the stream later.
1.54 + * It is an error to call {@link #reset(long)} after consuming more than
1.55 + * {@code readLimit} bytes from this stream.
1.56 + */
1.57 + public long savePosition(int readLimit) {
1.58 + long offsetLimit = offset + readLimit;
1.59 + if (limit < offsetLimit) {
1.60 + setLimit(offsetLimit);
1.61 + }
1.62 + return offset;
1.63 + }
1.64 +
1.65 + /**
1.66 + * Makes sure that the underlying stream can backtrack the full range from
1.67 + * {@code reset} thru {@code limit}. Since we can't call {@code mark()}
1.68 + * without also adjusting the reset-to-position on the underlying stream this
1.69 + * method resets first and then marks the union of the two byte ranges. On
1.70 + * buffered streams this additional cursor motion shouldn't result in any
1.71 + * additional I/O.
1.72 + */
1.73 + private void setLimit(long limit) {
1.74 + try {
1.75 + if (reset < offset && offset <= this.limit) {
1.76 + in.reset();
1.77 + in.mark((int) (limit - reset));
1.78 + skip(reset, offset);
1.79 + } else {
1.80 + reset = offset;
1.81 + in.mark((int) (limit - offset));
1.82 + }
1.83 + this.limit = limit;
1.84 + } catch (IOException e) {
1.85 + throw new IllegalStateException("Unable to mark: " + e);
1.86 + }
1.87 + }
1.88 +
1.89 + /** Resets the stream to the most recent {@link #mark mark}. */
1.90 + @Override public void reset() throws IOException {
1.91 + reset(defaultMark);
1.92 + }
1.93 +
1.94 + /** Resets the stream to the position recorded by {@code token}. */
1.95 + public void reset(long token) throws IOException {
1.96 + if (offset > limit || token < reset) {
1.97 + throw new IOException("Cannot reset");
1.98 + }
1.99 + in.reset();
1.100 + skip(reset, token);
1.101 + offset = token;
1.102 + }
1.103 +
1.104 + /** Skips {@code target - current} bytes and returns. */
1.105 + private void skip(long current, long target) throws IOException {
1.106 + while (current < target) {
1.107 + long skipped = in.skip(target - current);
1.108 + if (skipped == 0) {
1.109 + if (read() == -1) {
1.110 + break; // EOF
1.111 + } else {
1.112 + skipped = 1;
1.113 + }
1.114 + }
1.115 + current += skipped;
1.116 + }
1.117 + }
1.118 +
1.119 + @Override public int read() throws IOException {
1.120 + int result = in.read();
1.121 + if (result != -1) {
1.122 + offset++;
1.123 + }
1.124 + return result;
1.125 + }
1.126 +
1.127 + @Override public int read(byte[] buffer) throws IOException {
1.128 + int count = in.read(buffer);
1.129 + if (count != -1) {
1.130 + offset += count;
1.131 + }
1.132 + return count;
1.133 + }
1.134 +
1.135 + @Override public int read(byte[] buffer, int offset, int length) throws IOException {
1.136 + int count = in.read(buffer, offset, length);
1.137 + if (count != -1) {
1.138 + this.offset += count;
1.139 + }
1.140 + return count;
1.141 + }
1.142 +
1.143 + @Override public long skip(long byteCount) throws IOException {
1.144 + long skipped = in.skip(byteCount);
1.145 + offset += skipped;
1.146 + return skipped;
1.147 + }
1.148 +
1.149 + @Override public int available() throws IOException {
1.150 + return in.available();
1.151 + }
1.152 +
1.153 + @Override public void close() throws IOException {
1.154 + in.close();
1.155 + }
1.156 +
1.157 + @Override public boolean markSupported() {
1.158 + return in.markSupported();
1.159 + }
1.160 +}
