Package com.google.protobuf

Class CodedInputStream

java.lang.Object
com.google.protobuf.CodedInputStream
public abstract class CodedInputStream extends Object
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. readTag() and readInt32()) and methods that read low-level values (e.g. readRawVarint32() and readRawBytes(int)). 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.

  • Method Details

    • newInstance

      public static CodedInputStream newInstance(InputStream input)
      Create a new CodedInputStream wrapping the given InputStream.

    • newInstance

      public static CodedInputStream newInstance(InputStream input, int bufferSize)
      Create a new CodedInputStream wrapping the given InputStream, with a specified buffer size.

    • newInstance

      public static CodedInputStream newInstance(Iterable<ByteBuffer> input)
      Create a new CodedInputStream wrapping the given Iterable <ByteBuffer>.

    • newInstance

      public static CodedInputStream newInstance(byte[] buf)
      Create a new CodedInputStream wrapping the given byte array.

    • newInstance

      public static CodedInputStream newInstance(byte[] buf, int off, int len)
      Create a new CodedInputStream wrapping the given byte array slice.

    • newInstance

      public static CodedInputStream newInstance(ByteBuffer buf)
      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.

    • checkRecursionLimit

      public void checkRecursionLimit() throws InvalidProtocolBufferException
      Throws:
      InvalidProtocolBufferException

    • checkValidEndTag

      public void checkValidEndTag() throws InvalidProtocolBufferException
      Verifies that the last tag was 0 if we aren't inside a group.
      Throws:
      InvalidProtocolBufferException - The last tag was not 0 and we aren't inside a group.

    • readTag

      public abstract int readTag() throws IOException
      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.
      Throws:
      IOException

    • checkLastTagWas

      public abstract void checkLastTagWas(int value) throws InvalidProtocolBufferException
      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 - value does not match the last tag.

    • getLastTag

      public abstract int getLastTag()

    • skipField

      public abstract boolean skipField(int tag) throws IOException
      Reads and discards a single field, given its tag value.
      Returns:
      false if the tag is an endgroup tag, in which case nothing is skipped. Otherwise, returns true.
      Throws:
      IOException

    • skipField

      @Deprecated public abstract boolean skipField(int tag, CodedOutputStream output) throws IOException
      Deprecated.
      use UnknownFieldSet or UnknownFieldSetLite to skip to an output stream.
      Reads a single field and writes it to output in wire format, given its tag value.
      Returns:
      false if the tag is an endgroup tag, in which case nothing is skipped. Otherwise, returns true.
      Throws:
      IOException

    • skipMessage

      public void skipMessage() throws IOException
      Reads and discards an entire message. This will read either until EOF or until an endgroup tag, whichever comes first.
      Throws:
      IOException

    • skipMessage

      public void skipMessage(CodedOutputStream output) throws IOException
      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.
      Throws:
      IOException

    • readDouble

      public abstract double readDouble() throws IOException
      Read a double field value from the stream.
      Throws:
      IOException

    • readFloat

      public abstract float readFloat() throws IOException
      Read a float field value from the stream.
      Throws:
      IOException

    • readUInt64

      public abstract long readUInt64() throws IOException
      Read a uint64 field value from the stream.
      Throws:
      IOException

    • readInt64

      public abstract long readInt64() throws IOException
      Read an int64 field value from the stream.
      Throws:
      IOException

    • readInt32

      public abstract int readInt32() throws IOException
      Read an int32 field value from the stream.
      Throws:
      IOException

    • readFixed64

      public abstract long readFixed64() throws IOException
      Read a fixed64 field value from the stream.
      Throws:
      IOException

    • readFixed32

      public abstract int readFixed32() throws IOException
      Read a fixed32 field value from the stream.
      Throws:
      IOException

    • readBool

      public abstract boolean readBool() throws IOException
      Read a bool field value from the stream.
      Throws:
      IOException

    • readString

      public abstract String readString() throws IOException
      Read a string field value from the stream. If the stream contains malformed UTF-8, replace the offending bytes with the standard UTF-8 replacement character.
      Throws:
      IOException

    • readStringRequireUtf8

      public abstract String readStringRequireUtf8() throws IOException
      Read a string field value from the stream. If the stream contains malformed UTF-8, throw exception InvalidProtocolBufferException.
      Throws:
      IOException

    • readGroup

      public abstract void readGroup(int fieldNumber, MessageLite.Builder builder, ExtensionRegistryLite extensionRegistry) throws IOException
      Read a group field value from the stream.
      Throws:
      IOException

    • readGroup

      public abstract <T extends MessageLite> T readGroup(int fieldNumber, Parser<T> parser, ExtensionRegistryLite extensionRegistry) throws IOException
      Read a group field value from the stream.
      Throws:
      IOException

    • readUnknownGroup

      @Deprecated public abstract void readUnknownGroup(int fieldNumber, MessageLite.Builder builder) throws IOException
      Deprecated.
      UnknownFieldSet.Builder now implements MessageLite.Builder, so you can just call readGroup(int, com.google.protobuf.MessageLite.Builder, com.google.protobuf.ExtensionRegistryLite).
      Reads a group field value from the stream and merges it into the given UnknownFieldSet.
      Throws:
      IOException

    • readMessage

      public abstract void readMessage(MessageLite.Builder builder, ExtensionRegistryLite extensionRegistry) throws IOException
      Read an embedded message field value from the stream.
      Throws:
      IOException

    • readMessage

      public abstract <T extends MessageLite> T readMessage(Parser<T> parser, ExtensionRegistryLite extensionRegistry) throws IOException
      Read an embedded message field value from the stream.
      Throws:
      IOException

    • readBytes

      public abstract ByteString readBytes() throws IOException
      Read a bytes field value from the stream.
      Throws:
      IOException

    • readByteArray

      public abstract byte[] readByteArray() throws IOException
      Read a bytes field value from the stream.
      Throws:
      IOException

    • readByteBuffer

      public abstract ByteBuffer readByteBuffer() throws IOException
      Read a bytes field value from the stream.
      Throws:
      IOException

    • readUInt32

      public abstract int readUInt32() throws IOException
      Read a uint32 field value from the stream.
      Throws:
      IOException

    • readEnum

      public abstract int readEnum() throws IOException
      Read an enum field value from the stream. Caller is responsible for converting the numeric value to an actual enum.
      Throws:
      IOException

    • readSFixed32

      public abstract int readSFixed32() throws IOException
      Read an sfixed32 field value from the stream.
      Throws:
      IOException

    • readSFixed64

      public abstract long readSFixed64() throws IOException
      Read an sfixed64 field value from the stream.
      Throws:
      IOException

    • readSInt32

      public abstract int readSInt32() throws IOException
      Read an sint32 field value from the stream.
      Throws:
      IOException

    • readSInt64

      public abstract long readSInt64() throws IOException
      Read an sint64 field value from the stream.
      Throws:
      IOException

    • readRawVarint32

      public abstract int readRawVarint32() throws IOException
      Read a raw Varint from the stream. If larger than 32 bits, discard the upper bits.
      Throws:
      IOException

    • readRawVarint64

      public abstract long readRawVarint64() throws IOException
      Read a raw Varint from the stream.
      Throws:
      IOException

    • readRawLittleEndian32

      public abstract int readRawLittleEndian32() throws IOException
      Read a 32-bit little-endian integer from the stream.
      Throws:
      IOException

    • readRawLittleEndian64

      public abstract long readRawLittleEndian64() throws IOException
      Read a 64-bit little-endian integer from the stream.
      Throws:
      IOException

    • enableAliasing

      public abstract void enableAliasing(boolean enabled)
      Enables ByteString aliasing of the underlying buffer, trading off on buffer pinning for data copies. Only valid for buffer-backed streams.

    • setRecursionLimit

      public final int setRecursionLimit(int limit)
      Set the maximum message recursion depth. In order to prevent malicious messages from causing stack overflows, CodedInputStream limits how deeply messages may be nested. The default limit is 100.
      Returns:
      the old limit.

    • setSizeLimit

      public final int setSizeLimit(int limit)
      Only valid for InputStream-backed streams.

      Set the maximum message size. In order to prevent malicious messages from exhausting memory or causing integer overflows, CodedInputStream limits how large a message may be. The default limit is Integer.MAX_VALUE. 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 InputStream, not when constructed around a raw byte array.

      If you want to read several messages from a single CodedInputStream, you could call resetSizeCounter() after each one to avoid hitting the size limit.

      Returns:
      the old limit.

    • resetSizeCounter

      public abstract void resetSizeCounter()
      Resets the current size counter to zero (see setSizeLimit(int)). Only valid for InputStream-backed streams.

    • pushLimit

      public abstract int pushLimit(int byteLimit) throws InvalidProtocolBufferException
      Sets currentLimit to (current position) + byteLimit. This is called when descending into a length-delimited embedded message.

      Note that pushLimit() does NOT affect how many bytes the CodedInputStream reads from an underlying InputStream when refreshing its buffer. If you need to prevent reading past a certain point in the underlying 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 InputStream which limits the amount of data that can be read from it.

      Returns:
      the old limit.
      Throws:
      InvalidProtocolBufferException

    • popLimit

      public abstract void popLimit(int oldLimit)
      Discards the current limit, returning to the previous limit.
      Parameters:
      oldLimit - The old limit, as returned by pushLimit.

    • getBytesUntilLimit

      public abstract int getBytesUntilLimit()
      Returns the number of bytes to be read before the current limit. If no limit is set, returns -1.

    • isAtEnd

      public abstract boolean isAtEnd() throws IOException
      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 pushLimit(int). This function may get blocked when using StreamDecoder as it invokes CodedInputStream.StreamDecoder.tryRefillBuffer(int) in this function which will try to read bytes from input.
      Throws:
      IOException

    • getTotalBytesRead

      public abstract int getTotalBytesRead()
      The total bytes read up to the current position. Calling resetSizeCounter() resets this value to zero.

    • readRawByte

      public abstract byte readRawByte() throws IOException
      Read one byte from the input.
      Throws:
      InvalidProtocolBufferException - The end of the stream or the current limit was reached.
      IOException

    • readRawBytes

      public abstract byte[] readRawBytes(int size) throws IOException
      Read a fixed size of bytes from the input.
      Throws:
      InvalidProtocolBufferException - The end of the stream or the current limit was reached.
      IOException

    • skipRawBytes

      public abstract void skipRawBytes(int size) throws IOException
      Reads and discards size bytes.
      Throws:
      InvalidProtocolBufferException - The end of the stream or the current limit was reached.
      IOException

    • decodeZigZag32

      public static int decodeZigZag32(int n)
      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.)
      Parameters:
      n - An unsigned 32-bit integer, stored in a signed int because Java has no explicit unsigned support.
      Returns:
      A signed 32-bit integer.

    • decodeZigZag64

      public static long decodeZigZag64(long n)
      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.)
      Parameters:
      n - An unsigned 64-bit integer, stored in a signed int because Java has no explicit unsigned support.
      Returns:
      A signed 64-bit integer.

    • readRawVarint32

      public static int readRawVarint32(int firstByte, InputStream input) throws IOException
      Like 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.
      Throws:
      IOException