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-rw-r--r--mobile/android/thirdparty/com/squareup/picasso/MarkableInputStream.java157
1 files changed, 157 insertions, 0 deletions
diff --git a/mobile/android/thirdparty/com/squareup/picasso/MarkableInputStream.java b/mobile/android/thirdparty/com/squareup/picasso/MarkableInputStream.java
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+++ b/mobile/android/thirdparty/com/squareup/picasso/MarkableInputStream.java
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+/*
+ * Copyright (C) 2013 Square, Inc.
+ *
+ * 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.squareup.picasso;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * An input stream wrapper that supports unlimited independent cursors for
+ * marking and resetting. Each cursor is a token, and it's the caller's
+ * responsibility to keep track of these.
+ */
+final class MarkableInputStream extends InputStream {
+ private final InputStream in;
+
+ private long offset;
+ private long reset;
+ private long limit;
+
+ private long defaultMark = -1;
+
+ public MarkableInputStream(InputStream in) {
+ if (!in.markSupported()) {
+ in = new BufferedInputStream(in);
+ }
+ this.in = in;
+ }
+
+ /** Marks this place in the stream so we can reset back to it later. */
+ @Override public void mark(int readLimit) {
+ defaultMark = savePosition(readLimit);
+ }
+
+ /**
+ * Returns an opaque token representing the current position in the stream.
+ * Call {@link #reset(long)} to return to this position in the stream later.
+ * It is an error to call {@link #reset(long)} after consuming more than
+ * {@code readLimit} bytes from this stream.
+ */
+ public long savePosition(int readLimit) {
+ long offsetLimit = offset + readLimit;
+ if (limit < offsetLimit) {
+ setLimit(offsetLimit);
+ }
+ return offset;
+ }
+
+ /**
+ * Makes sure that the underlying stream can backtrack the full range from
+ * {@code reset} thru {@code limit}. Since we can't call {@code mark()}
+ * without also adjusting the reset-to-position on the underlying stream this
+ * method resets first and then marks the union of the two byte ranges. On
+ * buffered streams this additional cursor motion shouldn't result in any
+ * additional I/O.
+ */
+ private void setLimit(long limit) {
+ try {
+ if (reset < offset && offset <= this.limit) {
+ in.reset();
+ in.mark((int) (limit - reset));
+ skip(reset, offset);
+ } else {
+ reset = offset;
+ in.mark((int) (limit - offset));
+ }
+ this.limit = limit;
+ } catch (IOException e) {
+ throw new IllegalStateException("Unable to mark: " + e);
+ }
+ }
+
+ /** Resets the stream to the most recent {@link #mark mark}. */
+ @Override public void reset() throws IOException {
+ reset(defaultMark);
+ }
+
+ /** Resets the stream to the position recorded by {@code token}. */
+ public void reset(long token) throws IOException {
+ if (offset > limit || token < reset) {
+ throw new IOException("Cannot reset");
+ }
+ in.reset();
+ skip(reset, token);
+ offset = token;
+ }
+
+ /** Skips {@code target - current} bytes and returns. */
+ private void skip(long current, long target) throws IOException {
+ while (current < target) {
+ long skipped = in.skip(target - current);
+ if (skipped == 0) {
+ if (read() == -1) {
+ break; // EOF
+ } else {
+ skipped = 1;
+ }
+ }
+ current += skipped;
+ }
+ }
+
+ @Override public int read() throws IOException {
+ int result = in.read();
+ if (result != -1) {
+ offset++;
+ }
+ return result;
+ }
+
+ @Override public int read(byte[] buffer) throws IOException {
+ int count = in.read(buffer);
+ if (count != -1) {
+ offset += count;
+ }
+ return count;
+ }
+
+ @Override public int read(byte[] buffer, int offset, int length) throws IOException {
+ int count = in.read(buffer, offset, length);
+ if (count != -1) {
+ this.offset += count;
+ }
+ return count;
+ }
+
+ @Override public long skip(long byteCount) throws IOException {
+ long skipped = in.skip(byteCount);
+ offset += skipped;
+ return skipped;
+ }
+
+ @Override public int available() throws IOException {
+ return in.available();
+ }
+
+ @Override public void close() throws IOException {
+ in.close();
+ }
+
+ @Override public boolean markSupported() {
+ return in.markSupported();
+ }
+}