// Protocol Buffers - Google's data interchange format // Copyright 2008 Google Inc. All rights reserved. // http://code.google.com/p/protobuf/ // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. package com.google.protobuf; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.ByteBuffer; import java.util.ArrayList; import java.util.Arrays; import java.util.List; /** * Reads and decodes protocol message fields. * * This class contains two kinds of methods: methods that read specific * protocol message constructs and field types (e.g. {@link #readTag()} and * {@link #readInt32()}) and methods that read low-level values (e.g. * {@link #readRawVarint32()} and {@link #readRawBytes}). If you are reading * encoded protocol messages, you should use the former methods, but if you are * reading some other format of your own design, use the latter. * * @author kenton@google.com Kenton Varda */ public final class CodedInputStream { /** * Create a new CodedInputStream wrapping the given InputStream. */ public static CodedInputStream newInstance(final InputStream input) { return new CodedInputStream(input); } /** * Create a new CodedInputStream wrapping the given byte array. */ public static CodedInputStream newInstance(final byte[] buf) { return newInstance(buf, 0, buf.length); } /** * Create a new CodedInputStream wrapping the given byte array slice. */ public static CodedInputStream newInstance(final byte[] buf, final int off, final int len) { CodedInputStream result = new CodedInputStream(buf, off, len); try { // Some uses of CodedInputStream can be more efficient if they know // exactly how many bytes are available. By pushing the end point of the // buffer as a limit, we allow them to get this information via // getBytesUntilLimit(). Pushing a limit that we know is at the end of // the stream can never hurt, since we can never past that point anyway. result.pushLimit(len); } catch (InvalidProtocolBufferException ex) { // The only reason pushLimit() might throw an exception here is if len // is negative. Normally pushLimit()'s parameter comes directly off the // wire, so it's important to catch exceptions in case of corrupt or // malicious data. However, in this case, we expect that len is not a // user-supplied value, so we can assume that it being negative indicates // a programming error. Therefore, throwing an unchecked exception is // appropriate. throw new IllegalArgumentException(ex); } return result; } /** * Create a new CodedInputStream wrapping the given ByteBuffer. The data * starting from the ByteBuffer's current position to its limit will be read. * The returned CodedInputStream may or may not share the underlying data * in the ByteBuffer, therefore the ByteBuffer cannot be changed while the * CodedInputStream is in use. * Note that the ByteBuffer's position won't be changed by this function. * Concurrent calls with the same ByteBuffer object are safe if no other * thread is trying to alter the ByteBuffer's status. */ public static CodedInputStream newInstance(ByteBuffer buf) { if (buf.hasArray()) { return newInstance(buf.array(), buf.arrayOffset() + buf.position(), buf.remaining()); } else { ByteBuffer temp = buf.duplicate(); byte[] buffer = new byte[temp.remaining()]; temp.get(buffer); return newInstance(buffer); } } /** * Create a new CodedInputStream wrapping a LiteralByteString. */ static CodedInputStream newInstance(LiteralByteString byteString) { CodedInputStream result = new CodedInputStream(byteString); try { // Some uses of CodedInputStream can be more efficient if they know // exactly how many bytes are available. By pushing the end point of the // buffer as a limit, we allow them to get this information via // getBytesUntilLimit(). Pushing a limit that we know is at the end of // the stream can never hurt, since we can never past that point anyway. result.pushLimit(byteString.size()); } catch (InvalidProtocolBufferException ex) { // The only reason pushLimit() might throw an exception here is if len // is negative. Normally pushLimit()'s parameter comes directly off the // wire, so it's important to catch exceptions in case of corrupt or // malicious data. However, in this case, we expect that len is not a // user-supplied value, so we can assume that it being negative indicates // a programming error. Therefore, throwing an unchecked exception is // appropriate. throw new IllegalArgumentException(ex); } return result; } // ----------------------------------------------------------------- /** * Attempt to read a field tag, returning zero if we have reached EOF. * Protocol message parsers use this to read tags, since a protocol message * may legally end wherever a tag occurs, and zero is not a valid tag number. */ public int readTag() throws IOException { if (isAtEnd()) { lastTag = 0; return 0; } lastTag = readRawVarint32(); if (WireFormat.getTagFieldNumber(lastTag) == 0) { // If we actually read zero (or any tag number corresponding to field // number zero), that's not a valid tag. throw InvalidProtocolBufferException.invalidTag(); } return lastTag; } /** * Verifies that the last call to readTag() returned the given tag value. * This is used to verify that a nested group ended with the correct * end tag. * * @throws InvalidProtocolBufferException {@code value} does not match the * last tag. */ public void checkLastTagWas(final int value) throws InvalidProtocolBufferException { if (lastTag != value) { throw InvalidProtocolBufferException.invalidEndTag(); } } public int getLastTag() { return lastTag; } /** * Reads and discards a single field, given its tag value. * * @return {@code false} if the tag is an endgroup tag, in which case * nothing is skipped. Otherwise, returns {@code true}. */ public boolean skipField(final int tag) throws IOException { switch (WireFormat.getTagWireType(tag)) { case WireFormat.WIRETYPE_VARINT: skipRawVarint(); return true; case WireFormat.WIRETYPE_FIXED64: skipRawBytes(8); return true; case WireFormat.WIRETYPE_LENGTH_DELIMITED: skipRawBytes(readRawVarint32()); return true; case WireFormat.WIRETYPE_START_GROUP: skipMessage(); checkLastTagWas( WireFormat.makeTag(WireFormat.getTagFieldNumber(tag), WireFormat.WIRETYPE_END_GROUP)); return true; case WireFormat.WIRETYPE_END_GROUP: return false; case WireFormat.WIRETYPE_FIXED32: skipRawBytes(4); return true; default: throw InvalidProtocolBufferException.invalidWireType(); } } /** * Reads a single field and writes it to output in wire format, * given its tag value. * * @return {@code false} if the tag is an endgroup tag, in which case * nothing is skipped. Otherwise, returns {@code true}. */ public boolean skipField(final int tag, final CodedOutputStream output) throws IOException { switch (WireFormat.getTagWireType(tag)) { case WireFormat.WIRETYPE_VARINT: { long value = readInt64(); output.writeRawVarint32(tag); output.writeUInt64NoTag(value); return true; } case WireFormat.WIRETYPE_FIXED64: { long value = readRawLittleEndian64(); output.writeRawVarint32(tag); output.writeFixed64NoTag(value); return true; } case WireFormat.WIRETYPE_LENGTH_DELIMITED: { ByteString value = readBytes(); output.writeRawVarint32(tag); output.writeBytesNoTag(value); return true; } case WireFormat.WIRETYPE_START_GROUP: { output.writeRawVarint32(tag); skipMessage(output); int endtag = WireFormat.makeTag(WireFormat.getTagFieldNumber(tag), WireFormat.WIRETYPE_END_GROUP); checkLastTagWas(endtag); output.writeRawVarint32(endtag); return true; } case WireFormat.WIRETYPE_END_GROUP: { return false; } case WireFormat.WIRETYPE_FIXED32: { int value = readRawLittleEndian32(); output.writeRawVarint32(tag); output.writeFixed32NoTag(value); return true; } default: throw InvalidProtocolBufferException.invalidWireType(); } } /** * Reads and discards an entire message. This will read either until EOF * or until an endgroup tag, whichever comes first. */ public void skipMessage() throws IOException { while (true) { final int tag = readTag(); if (tag == 0 || !skipField(tag)) { return; } } } /** * Reads an entire message and writes it to output in wire format. * This will read either until EOF or until an endgroup tag, * whichever comes first. */ public void skipMessage(CodedOutputStream output) throws IOException { while (true) { final int tag = readTag(); if (tag == 0 || !skipField(tag, output)) { return; } } } /** * Collects the bytes skipped and returns the data in a ByteBuffer. */ private class SkippedDataSink implements RefillCallback { private int lastPos = bufferPos; private ByteArrayOutputStream byteArrayStream; @Override public void onRefill() { if (byteArrayStream == null) { byteArrayStream = new ByteArrayOutputStream(); } byteArrayStream.write(buffer, lastPos, bufferPos - lastPos); lastPos = 0; } /** * Gets skipped data in a ByteBuffer. This method should only be * called once. */ ByteBuffer getSkippedData() { if (byteArrayStream == null) { return ByteBuffer.wrap(buffer, lastPos, bufferPos - lastPos); } else { byteArrayStream.write(buffer, lastPos, bufferPos); return ByteBuffer.wrap(byteArrayStream.toByteArray()); } } } // ----------------------------------------------------------------- /** Read a {@code double} field value from the stream. */ public double readDouble() throws IOException { return Double.longBitsToDouble(readRawLittleEndian64()); } /** Read a {@code float} field value from the stream. */ public float readFloat() throws IOException { return Float.intBitsToFloat(readRawLittleEndian32()); } /** Read a {@code uint64} field value from the stream. */ public long readUInt64() throws IOException { return readRawVarint64(); } /** Read an {@code int64} field value from the stream. */ public long readInt64() throws IOException { return readRawVarint64(); } /** Read an {@code int32} field value from the stream. */ public int readInt32() throws IOException { return readRawVarint32(); } /** Read a {@code fixed64} field value from the stream. */ public long readFixed64() throws IOException { return readRawLittleEndian64(); } /** Read a {@code fixed32} field value from the stream. */ public int readFixed32() throws IOException { return readRawLittleEndian32(); } /** Read a {@code bool} field value from the stream. */ public boolean readBool() throws IOException { return readRawVarint64() != 0; } /** * Read a {@code string} field value from the stream. * If the stream contains malformed UTF-8, * replace the offending bytes with the standard UTF-8 replacement character. */ public String readString() throws IOException { final int size = readRawVarint32(); if (size <= (bufferSize - bufferPos) && size > 0) { // Fast path: We already have the bytes in a contiguous buffer, so // just copy directly from it. final String result = new String(buffer, bufferPos, size, "UTF-8"); bufferPos += size; return result; } else if (size == 0) { return ""; } else { // Slow path: Build a byte array first then copy it. return new String(readRawBytesSlowPath(size), "UTF-8"); } } /** * Read a {@code string} field value from the stream. * If the stream contains malformed UTF-8, * throw exception {@link InvalidProtocolBufferException}. */ public String readStringRequireUtf8() throws IOException { final int size = readRawVarint32(); final byte[] bytes; int pos = bufferPos; if (size <= (bufferSize - pos) && size > 0) { // Fast path: We already have the bytes in a contiguous buffer, so // just copy directly from it. bytes = buffer; bufferPos = pos + size; } else if (size == 0) { return ""; } else { // Slow path: Build a byte array first then copy it. bytes = readRawBytesSlowPath(size); pos = 0; } // TODO(martinrb): We could save a pass by validating while decoding. if (!Utf8.isValidUtf8(bytes, pos, pos + size)) { throw InvalidProtocolBufferException.invalidUtf8(); } return new String(bytes, pos, size, "UTF-8"); } /** Read a {@code group} field value from the stream. */ public void readGroup(final int fieldNumber, final MessageLite.Builder builder, final ExtensionRegistryLite extensionRegistry) throws IOException { if (recursionDepth >= recursionLimit) { throw InvalidProtocolBufferException.recursionLimitExceeded(); } ++recursionDepth; builder.mergeFrom(this, extensionRegistry); checkLastTagWas( WireFormat.makeTag(fieldNumber, WireFormat.WIRETYPE_END_GROUP)); --recursionDepth; } /** Read a {@code group} field value from the stream. */ public <T extends MessageLite> T readGroup( final int fieldNumber, final Parser<T> parser, final ExtensionRegistryLite extensionRegistry) throws IOException { if (recursionDepth >= recursionLimit) { throw InvalidProtocolBufferException.recursionLimitExceeded(); } ++recursionDepth; T result = parser.parsePartialFrom(this, extensionRegistry); checkLastTagWas( WireFormat.makeTag(fieldNumber, WireFormat.WIRETYPE_END_GROUP)); --recursionDepth; return result; } /** * Reads a {@code group} field value from the stream and merges it into the * given {@link UnknownFieldSet}. * * @deprecated UnknownFieldSet.Builder now implements MessageLite.Builder, so * you can just call {@link #readGroup}. */ @Deprecated public void readUnknownGroup(final int fieldNumber, final MessageLite.Builder builder) throws IOException { // We know that UnknownFieldSet will ignore any ExtensionRegistry so it // is safe to pass null here. (We can't call // ExtensionRegistry.getEmptyRegistry() because that would make this // class depend on ExtensionRegistry, which is not part of the lite // library.) readGroup(fieldNumber, builder, null); } /** Read an embedded message field value from the stream. */ public void readMessage(final MessageLite.Builder builder, final ExtensionRegistryLite extensionRegistry) throws IOException { final int length = readRawVarint32(); if (recursionDepth >= recursionLimit) { throw InvalidProtocolBufferException.recursionLimitExceeded(); } final int oldLimit = pushLimit(length); ++recursionDepth; builder.mergeFrom(this, extensionRegistry); checkLastTagWas(0); --recursionDepth; popLimit(oldLimit); } /** Read an embedded message field value from the stream. */ public <T extends MessageLite> T readMessage( final Parser<T> parser, final ExtensionRegistryLite extensionRegistry) throws IOException { int length = readRawVarint32(); if (recursionDepth >= recursionLimit) { throw InvalidProtocolBufferException.recursionLimitExceeded(); } final int oldLimit = pushLimit(length); ++recursionDepth; T result = parser.parsePartialFrom(this, extensionRegistry); checkLastTagWas(0); --recursionDepth; popLimit(oldLimit); return result; } /** Read a {@code bytes} field value from the stream. */ public ByteString readBytes() throws IOException { final int size = readRawVarint32(); if (size <= (bufferSize - bufferPos) && size > 0) { // Fast path: We already have the bytes in a contiguous buffer, so // just copy directly from it. final ByteString result = bufferIsImmutable && enableAliasing ? new BoundedByteString(buffer, bufferPos, size) : ByteString.copyFrom(buffer, bufferPos, size); bufferPos += size; return result; } else if (size == 0) { return ByteString.EMPTY; } else { // Slow path: Build a byte array first then copy it. return new LiteralByteString(readRawBytesSlowPath(size)); } } /** Read a {@code bytes} field value from the stream. */ public byte[] readByteArray() throws IOException { final int size = readRawVarint32(); if (size <= (bufferSize - bufferPos) && size > 0) { // Fast path: We already have the bytes in a contiguous buffer, so // just copy directly from it. final byte[] result = Arrays.copyOfRange(buffer, bufferPos, bufferPos + size); bufferPos += size; return result; } else { // Slow path: Build a byte array first then copy it. return readRawBytesSlowPath(size); } } /** Read a {@code bytes} field value from the stream. */ public ByteBuffer readByteBuffer() throws IOException { final int size = readRawVarint32(); if (size <= (bufferSize - bufferPos) && size > 0) { // Fast path: We already have the bytes in a contiguous buffer. // When aliasing is enabled, we can return a ByteBuffer pointing directly // into the underlying byte array without copy if the CodedInputStream is // constructed from a byte array. If aliasing is disabled or the input is // from an InputStream or ByteString, we have to make a copy of the bytes. ByteBuffer result = input == null && !bufferIsImmutable && enableAliasing ? ByteBuffer.wrap(buffer, bufferPos, size).slice() : ByteBuffer.wrap(Arrays.copyOfRange( buffer, bufferPos, bufferPos + size)); bufferPos += size; return result; } else if (size == 0) { return Internal.EMPTY_BYTE_BUFFER; } else { // Slow path: Build a byte array first then copy it. return ByteBuffer.wrap(readRawBytesSlowPath(size)); } } /** Read a {@code uint32} field value from the stream. */ public int readUInt32() throws IOException { return readRawVarint32(); } /** * Read an enum field value from the stream. Caller is responsible * for converting the numeric value to an actual enum. */ public int readEnum() throws IOException { return readRawVarint32(); } /** Read an {@code sfixed32} field value from the stream. */ public int readSFixed32() throws IOException { return readRawLittleEndian32(); } /** Read an {@code sfixed64} field value from the stream. */ public long readSFixed64() throws IOException { return readRawLittleEndian64(); } /** Read an {@code sint32} field value from the stream. */ public int readSInt32() throws IOException { return decodeZigZag32(readRawVarint32()); } /** Read an {@code sint64} field value from the stream. */ public long readSInt64() throws IOException { return decodeZigZag64(readRawVarint64()); } // ================================================================= /** * Read a raw Varint from the stream. If larger than 32 bits, discard the * upper bits. */ public int readRawVarint32() throws IOException { // See implementation notes for readRawVarint64 fastpath: { int pos = bufferPos; if (bufferSize == pos) { break fastpath; } final byte[] buffer = this.buffer; int x; if ((x = buffer[pos++]) >= 0) { bufferPos = pos; return x; } else if (bufferSize - pos < 9) { break fastpath; } else if ((x ^= (buffer[pos++] << 7)) < 0L) { x ^= (~0L << 7); } else if ((x ^= (buffer[pos++] << 14)) >= 0L) { x ^= (~0L << 7) ^ (~0L << 14); } else if ((x ^= (buffer[pos++] << 21)) < 0L) { x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21); } else { int y = buffer[pos++]; x ^= y << 28; x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28); if (y < 0 && buffer[pos++] < 0 && buffer[pos++] < 0 && buffer[pos++] < 0 && buffer[pos++] < 0 && buffer[pos++] < 0) { break fastpath; // Will throw malformedVarint() } } bufferPos = pos; return x; } return (int) readRawVarint64SlowPath(); } private void skipRawVarint() throws IOException { if (bufferSize - bufferPos >= 10) { final byte[] buffer = this.buffer; int pos = bufferPos; for (int i = 0; i < 10; i++) { if (buffer[pos++] >= 0) { bufferPos = pos; return; } } } skipRawVarintSlowPath(); } private void skipRawVarintSlowPath() throws IOException { for (int i = 0; i < 10; i++) { if (readRawByte() >= 0) { return; } } throw InvalidProtocolBufferException.malformedVarint(); } /** * Reads a varint from the input one byte at a time, so that it does not * read any bytes after the end of the varint. If you simply wrapped the * stream in a CodedInputStream and used {@link #readRawVarint32(InputStream)} * then you would probably end up reading past the end of the varint since * CodedInputStream buffers its input. */ static int readRawVarint32(final InputStream input) throws IOException { final int firstByte = input.read(); if (firstByte == -1) { throw InvalidProtocolBufferException.truncatedMessage(); } return readRawVarint32(firstByte, input); } /** * Like {@link #readRawVarint32(InputStream)}, but expects that the caller * has already read one byte. This allows the caller to determine if EOF * has been reached before attempting to read. */ public static int readRawVarint32( final int firstByte, final InputStream input) throws IOException { if ((firstByte & 0x80) == 0) { return firstByte; } int result = firstByte & 0x7f; int offset = 7; for (; offset < 32; offset += 7) { final int b = input.read(); if (b == -1) { throw InvalidProtocolBufferException.truncatedMessage(); } result |= (b & 0x7f) << offset; if ((b & 0x80) == 0) { return result; } } // Keep reading up to 64 bits. for (; offset < 64; offset += 7) { final int b = input.read(); if (b == -1) { throw InvalidProtocolBufferException.truncatedMessage(); } if ((b & 0x80) == 0) { return result; } } throw InvalidProtocolBufferException.malformedVarint(); } /** Read a raw Varint from the stream. */ public long readRawVarint64() throws IOException { // Implementation notes: // // Optimized for one-byte values, expected to be common. // The particular code below was selected from various candidates // empirically, by winning VarintBenchmark. // // Sign extension of (signed) Java bytes is usually a nuisance, but // we exploit it here to more easily obtain the sign of bytes read. // Instead of cleaning up the sign extension bits by masking eagerly, // we delay until we find the final (positive) byte, when we clear all // accumulated bits with one xor. We depend on javac to constant fold. fastpath: { int pos = bufferPos; if (bufferSize == pos) { break fastpath; } final byte[] buffer = this.buffer; long x; int y; if ((y = buffer[pos++]) >= 0) { bufferPos = pos; return y; } else if (bufferSize - pos < 9) { break fastpath; } else if ((x = y ^ (buffer[pos++] << 7)) < 0L) { x ^= (~0L << 7); } else if ((x ^= (buffer[pos++] << 14)) >= 0L) { x ^= (~0L << 7) ^ (~0L << 14); } else if ((x ^= (buffer[pos++] << 21)) < 0L) { x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21); } else if ((x ^= ((long) buffer[pos++] << 28)) >= 0L) { x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28); } else if ((x ^= ((long) buffer[pos++] << 35)) < 0L) { x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28) ^ (~0L << 35); } else if ((x ^= ((long) buffer[pos++] << 42)) >= 0L) { x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28) ^ (~0L << 35) ^ (~0L << 42); } else if ((x ^= ((long) buffer[pos++] << 49)) < 0L) { x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28) ^ (~0L << 35) ^ (~0L << 42) ^ (~0L << 49); } else { x ^= ((long) buffer[pos++] << 56); x ^= (~0L << 7) ^ (~0L << 14) ^ (~0L << 21) ^ (~0L << 28) ^ (~0L << 35) ^ (~0L << 42) ^ (~0L << 49) ^ (~0L << 56); if (x < 0L) { if (buffer[pos++] < 0L) { break fastpath; // Will throw malformedVarint() } } } bufferPos = pos; return x; } return readRawVarint64SlowPath(); } /** Variant of readRawVarint64 for when uncomfortably close to the limit. */ /* Visible for testing */ long readRawVarint64SlowPath() throws IOException { long result = 0; for (int shift = 0; shift < 64; shift += 7) { final byte b = readRawByte(); result |= (long) (b & 0x7F) << shift; if ((b & 0x80) == 0) { return result; } } throw InvalidProtocolBufferException.malformedVarint(); } /** Read a 32-bit little-endian integer from the stream. */ public int readRawLittleEndian32() throws IOException { int pos = bufferPos; // hand-inlined ensureAvailable(4); if (bufferSize - pos < 4) { refillBuffer(4); pos = bufferPos; } final byte[] buffer = this.buffer; bufferPos = pos + 4; return (((buffer[pos] & 0xff)) | ((buffer[pos + 1] & 0xff) << 8) | ((buffer[pos + 2] & 0xff) << 16) | ((buffer[pos + 3] & 0xff) << 24)); } /** Read a 64-bit little-endian integer from the stream. */ public long readRawLittleEndian64() throws IOException { int pos = bufferPos; // hand-inlined ensureAvailable(8); if (bufferSize - pos < 8) { refillBuffer(8); pos = bufferPos; } final byte[] buffer = this.buffer; bufferPos = pos + 8; return ((((long) buffer[pos] & 0xffL)) | (((long) buffer[pos + 1] & 0xffL) << 8) | (((long) buffer[pos + 2] & 0xffL) << 16) | (((long) buffer[pos + 3] & 0xffL) << 24) | (((long) buffer[pos + 4] & 0xffL) << 32) | (((long) buffer[pos + 5] & 0xffL) << 40) | (((long) buffer[pos + 6] & 0xffL) << 48) | (((long) buffer[pos + 7] & 0xffL) << 56)); } /** * Decode a ZigZag-encoded 32-bit value. ZigZag encodes signed integers * into values that can be efficiently encoded with varint. (Otherwise, * negative values must be sign-extended to 64 bits to be varint encoded, * thus always taking 10 bytes on the wire.) * * @param n An unsigned 32-bit integer, stored in a signed int because * Java has no explicit unsigned support. * @return A signed 32-bit integer. */ public static int decodeZigZag32(final int n) { return (n >>> 1) ^ -(n & 1); } /** * Decode a ZigZag-encoded 64-bit value. ZigZag encodes signed integers * into values that can be efficiently encoded with varint. (Otherwise, * negative values must be sign-extended to 64 bits to be varint encoded, * thus always taking 10 bytes on the wire.) * * @param n An unsigned 64-bit integer, stored in a signed int because * Java has no explicit unsigned support. * @return A signed 64-bit integer. */ public static long decodeZigZag64(final long n) { return (n >>> 1) ^ -(n & 1); } // ----------------------------------------------------------------- private final byte[] buffer; private final boolean bufferIsImmutable; private int bufferSize; private int bufferSizeAfterLimit; private int bufferPos; private final InputStream input; private int lastTag; private boolean enableAliasing = false; /** * The total number of bytes read before the current buffer. The total * bytes read up to the current position can be computed as * {@code totalBytesRetired + bufferPos}. This value may be negative if * reading started in the middle of the current buffer (e.g. if the * constructor that takes a byte array and an offset was used). */ private int totalBytesRetired; /** The absolute position of the end of the current message. */ private int currentLimit = Integer.MAX_VALUE; /** See setRecursionLimit() */ private int recursionDepth; private int recursionLimit = DEFAULT_RECURSION_LIMIT; /** See setSizeLimit() */ private int sizeLimit = DEFAULT_SIZE_LIMIT; private static final int DEFAULT_RECURSION_LIMIT = 64; private static final int DEFAULT_SIZE_LIMIT = 64 << 20; // 64MB private static final int BUFFER_SIZE = 4096; private CodedInputStream(final byte[] buffer, final int off, final int len) { this.buffer = buffer; bufferSize = off + len; bufferPos = off; totalBytesRetired = -off; input = null; bufferIsImmutable = false; } private CodedInputStream(final InputStream input) { buffer = new byte[BUFFER_SIZE]; bufferSize = 0; bufferPos = 0; totalBytesRetired = 0; this.input = input; bufferIsImmutable = false; } private CodedInputStream(final LiteralByteString byteString) { buffer = byteString.bytes; bufferPos = byteString.getOffsetIntoBytes(); bufferSize = bufferPos + byteString.size(); totalBytesRetired = -bufferPos; input = null; bufferIsImmutable = true; } public void enableAliasing(boolean enabled) { this.enableAliasing = enabled; } /** * Set the maximum message recursion depth. In order to prevent malicious * messages from causing stack overflows, {@code CodedInputStream} limits * how deeply messages may be nested. The default limit is 64. * * @return the old limit. */ public int setRecursionLimit(final int limit) { if (limit < 0) { throw new IllegalArgumentException( "Recursion limit cannot be negative: " + limit); } final int oldLimit = recursionLimit; recursionLimit = limit; return oldLimit; } /** * Set the maximum message size. In order to prevent malicious * messages from exhausting memory or causing integer overflows, * {@code CodedInputStream} limits how large a message may be. * The default limit is 64MB. You should set this limit as small * as you can without harming your app's functionality. Note that * size limits only apply when reading from an {@code InputStream}, not * when constructed around a raw byte array (nor with * {@link ByteString#newCodedInput}). * <p> * If you want to read several messages from a single CodedInputStream, you * could call {@link #resetSizeCounter()} after each one to avoid hitting the * size limit. * * @return the old limit. */ public int setSizeLimit(final int limit) { if (limit < 0) { throw new IllegalArgumentException( "Size limit cannot be negative: " + limit); } final int oldLimit = sizeLimit; sizeLimit = limit; return oldLimit; } /** * Resets the current size counter to zero (see {@link #setSizeLimit(int)}). */ public void resetSizeCounter() { totalBytesRetired = -bufferPos; } /** * Sets {@code currentLimit} to (current position) + {@code byteLimit}. This * is called when descending into a length-delimited embedded message. * * <p>Note that {@code pushLimit()} does NOT affect how many bytes the * {@code CodedInputStream} reads from an underlying {@code InputStream} when * refreshing its buffer. If you need to prevent reading past a certain * point in the underlying {@code InputStream} (e.g. because you expect it to * contain more data after the end of the message which you need to handle * differently) then you must place a wrapper around your {@code InputStream} * which limits the amount of data that can be read from it. * * @return the old limit. */ public int pushLimit(int byteLimit) throws InvalidProtocolBufferException { if (byteLimit < 0) { throw InvalidProtocolBufferException.negativeSize(); } byteLimit += totalBytesRetired + bufferPos; final int oldLimit = currentLimit; if (byteLimit > oldLimit) { throw InvalidProtocolBufferException.truncatedMessage(); } currentLimit = byteLimit; recomputeBufferSizeAfterLimit(); return oldLimit; } private void recomputeBufferSizeAfterLimit() { bufferSize += bufferSizeAfterLimit; final int bufferEnd = totalBytesRetired + bufferSize; if (bufferEnd > currentLimit) { // Limit is in current buffer. bufferSizeAfterLimit = bufferEnd - currentLimit; bufferSize -= bufferSizeAfterLimit; } else { bufferSizeAfterLimit = 0; } } /** * Discards the current limit, returning to the previous limit. * * @param oldLimit The old limit, as returned by {@code pushLimit}. */ public void popLimit(final int oldLimit) { currentLimit = oldLimit; recomputeBufferSizeAfterLimit(); } /** * Returns the number of bytes to be read before the current limit. * If no limit is set, returns -1. */ public int getBytesUntilLimit() { if (currentLimit == Integer.MAX_VALUE) { return -1; } final int currentAbsolutePosition = totalBytesRetired + bufferPos; return currentLimit - currentAbsolutePosition; } /** * Returns true if the stream has reached the end of the input. This is the * case if either the end of the underlying input source has been reached or * if the stream has reached a limit created using {@link #pushLimit(int)}. */ public boolean isAtEnd() throws IOException { return bufferPos == bufferSize && !tryRefillBuffer(1); } /** * The total bytes read up to the current position. Calling * {@link #resetSizeCounter()} resets this value to zero. */ public int getTotalBytesRead() { return totalBytesRetired + bufferPos; } private interface RefillCallback { void onRefill(); } private RefillCallback refillCallback = null; /** * Ensures that at least {@code n} bytes are available in the buffer, reading * more bytes from the input if necessary to make it so. Caller must ensure * that the requested space is less than BUFFER_SIZE. * * @throws InvalidProtocolBufferException The end of the stream or the current * limit was reached. */ private void ensureAvailable(int n) throws IOException { if (bufferSize - bufferPos < n) { refillBuffer(n); } } /** * Reads more bytes from the input, making at least {@code n} bytes available * in the buffer. Caller must ensure that the requested space is not yet * available, and that the requested space is less than BUFFER_SIZE. * * @throws InvalidProtocolBufferException The end of the stream or the current * limit was reached. */ private void refillBuffer(int n) throws IOException { if (!tryRefillBuffer(n)) { throw InvalidProtocolBufferException.truncatedMessage(); } } /** * Tries to read more bytes from the input, making at least {@code n} bytes * available in the buffer. Caller must ensure that the requested space is * not yet available, and that the requested space is less than BUFFER_SIZE. * * @return {@code true} if the bytes could be made available; {@code false} * if the end of the stream or the current limit was reached. */ private boolean tryRefillBuffer(int n) throws IOException { if (bufferPos + n <= bufferSize) { throw new IllegalStateException( "refillBuffer() called when " + n + " bytes were already available in buffer"); } if (totalBytesRetired + bufferPos + n > currentLimit) { // Oops, we hit a limit. return false; } if (refillCallback != null) { refillCallback.onRefill(); } if (input != null) { int pos = bufferPos; if (pos > 0) { if (bufferSize > pos) { System.arraycopy(buffer, pos, buffer, 0, bufferSize - pos); } totalBytesRetired += pos; bufferSize -= pos; bufferPos = 0; } int bytesRead = input.read(buffer, bufferSize, buffer.length - bufferSize); if (bytesRead == 0 || bytesRead < -1 || bytesRead > buffer.length) { throw new IllegalStateException( "InputStream#read(byte[]) returned invalid result: " + bytesRead + "\nThe InputStream implementation is buggy."); } if (bytesRead > 0) { bufferSize += bytesRead; // Integer-overflow-conscious check against sizeLimit if (totalBytesRetired + n - sizeLimit > 0) { throw InvalidProtocolBufferException.sizeLimitExceeded(); } recomputeBufferSizeAfterLimit(); return (bufferSize >= n) ? true : tryRefillBuffer(n); } } return false; } /** * Read one byte from the input. * * @throws InvalidProtocolBufferException The end of the stream or the current * limit was reached. */ public byte readRawByte() throws IOException { if (bufferPos == bufferSize) { refillBuffer(1); } return buffer[bufferPos++]; } /** * Read a fixed size of bytes from the input. * * @throws InvalidProtocolBufferException The end of the stream or the current * limit was reached. */ public byte[] readRawBytes(final int size) throws IOException { final int pos = bufferPos; if (size <= (bufferSize - pos) && size > 0) { bufferPos = pos + size; return Arrays.copyOfRange(buffer, pos, pos + size); } else { return readRawBytesSlowPath(size); } } /** * Exactly like readRawBytes, but caller must have already checked the fast * path: (size <= (bufferSize - pos) && size > 0) */ private byte[] readRawBytesSlowPath(final int size) throws IOException { if (size <= 0) { if (size == 0) { return Internal.EMPTY_BYTE_ARRAY; } else { throw InvalidProtocolBufferException.negativeSize(); } } if (totalBytesRetired + bufferPos + size > currentLimit) { // Read to the end of the stream anyway. skipRawBytes(currentLimit - totalBytesRetired - bufferPos); // Then fail. throw InvalidProtocolBufferException.truncatedMessage(); } if (size < BUFFER_SIZE) { // Reading more bytes than are in the buffer, but not an excessive number // of bytes. We can safely allocate the resulting array ahead of time. // First copy what we have. final byte[] bytes = new byte[size]; int pos = bufferSize - bufferPos; System.arraycopy(buffer, bufferPos, bytes, 0, pos); bufferPos = bufferSize; // We want to refill the buffer and then copy from the buffer into our // byte array rather than reading directly into our byte array because // the input may be unbuffered. ensureAvailable(size - pos); System.arraycopy(buffer, 0, bytes, pos, size - pos); bufferPos = size - pos; return bytes; } else { // The size is very large. For security reasons, we can't allocate the // entire byte array yet. The size comes directly from the input, so a // maliciously-crafted message could provide a bogus very large size in // order to trick the app into allocating a lot of memory. We avoid this // by allocating and reading only a small chunk at a time, so that the // malicious message must actually *be* extremely large to cause // problems. Meanwhile, we limit the allowed size of a message elsewhere. // Remember the buffer markers since we'll have to copy the bytes out of // it later. final int originalBufferPos = bufferPos; final int originalBufferSize = bufferSize; // Mark the current buffer consumed. totalBytesRetired += bufferSize; bufferPos = 0; bufferSize = 0; // Read all the rest of the bytes we need. int sizeLeft = size - (originalBufferSize - originalBufferPos); final List<byte[]> chunks = new ArrayList<byte[]>(); while (sizeLeft > 0) { final byte[] chunk = new byte[Math.min(sizeLeft, BUFFER_SIZE)]; int pos = 0; while (pos < chunk.length) { final int n = (input == null) ? -1 : input.read(chunk, pos, chunk.length - pos); if (n == -1) { throw InvalidProtocolBufferException.truncatedMessage(); } totalBytesRetired += n; pos += n; } sizeLeft -= chunk.length; chunks.add(chunk); } // OK, got everything. Now concatenate it all into one buffer. final byte[] bytes = new byte[size]; // Start by copying the leftover bytes from this.buffer. int pos = originalBufferSize - originalBufferPos; System.arraycopy(buffer, originalBufferPos, bytes, 0, pos); // And now all the chunks. for (final byte[] chunk : chunks) { System.arraycopy(chunk, 0, bytes, pos, chunk.length); pos += chunk.length; } // Done. return bytes; } } /** * Reads and discards {@code size} bytes. * * @throws InvalidProtocolBufferException The end of the stream or the current * limit was reached. */ public void skipRawBytes(final int size) throws IOException { if (size <= (bufferSize - bufferPos) && size >= 0) { // We have all the bytes we need already. bufferPos += size; } else { skipRawBytesSlowPath(size); } } /** * Exactly like skipRawBytes, but caller must have already checked the fast * path: (size <= (bufferSize - pos) && size >= 0) */ private void skipRawBytesSlowPath(final int size) throws IOException { if (size < 0) { throw InvalidProtocolBufferException.negativeSize(); } if (totalBytesRetired + bufferPos + size > currentLimit) { // Read to the end of the stream anyway. skipRawBytes(currentLimit - totalBytesRetired - bufferPos); // Then fail. throw InvalidProtocolBufferException.truncatedMessage(); } // Skipping more bytes than are in the buffer. First skip what we have. int pos = bufferSize - bufferPos; bufferPos = bufferSize; // Keep refilling the buffer until we get to the point we wanted to skip to. // This has the side effect of ensuring the limits are updated correctly. refillBuffer(1); while (size - pos > bufferSize) { pos += bufferSize; bufferPos = bufferSize; refillBuffer(1); } bufferPos = size - pos; } }