Class CodedInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable

    public final class CodedInputStream
    extends java.io.FilterInputStream
    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.
    Author:
    kenton@google.com Kenton Varda
    • Field Summary

      • Fields inherited from class java.io.FilterInputStream

        in
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void checkLastTagWas​(int value)
      Verifies that the last call to readTag() returned the given tag value.
      static int decodeZigZag32​(int n)
      Decode a ZigZag-encoded 32-bit value.
      static long decodeZigZag64​(long n)
      Decode a ZigZag-encoded 64-bit value.
      void popLimit​(int limit)  
      int pushLimit​(int limit)  
      boolean readBool()
      Read a bool field value from the stream.
      Buffer readBytes()
      Read a bytes field value from the stream.
      double readDouble()
      Read a double field value from the stream.
      int readEnum()
      Read an enum field value from the stream.
      int readFixed32()
      Read a fixed32 field value from the stream.
      long readFixed64()
      Read a fixed64 field value from the stream.
      float readFloat()
      Read a float field value from the stream.
      int readInt32()
      Read an int32 field value from the stream.
      long readInt64()
      Read an int64 field value from the stream.
      byte readRawByte()
      Read one byte from the input.
      Buffer readRawBytes​(int size)
      Read a fixed size of bytes from the input.
      int readRawLittleEndian32()
      Read a 32-bit little-endian integer from the stream.
      long readRawLittleEndian64()
      Read a 64-bit little-endian integer from the stream.
      int readRawVarint32()
      Read a raw Varint from the stream.
      long readRawVarint64()
      Read a raw Varint from the stream.
      int readSFixed32()
      Read an sfixed32 field value from the stream.
      long readSFixed64()
      Read an sfixed64 field value from the stream.
      int readSInt32()
      Read an sint32 field value from the stream.
      long readSInt64()
      Read an sint64 field value from the stream.
      java.lang.String readString()
      Read a string field value from the stream.
      int readTag()
      Attempt to read a field tag, returning zero if we have reached EOF.
      int readUInt32()
      Read a uint32 field value from the stream.
      long readUInt64()
      Read a uint64 field value from the stream.
      boolean skipField​(int tag)
      Reads and discards a single field, given its tag value.
      void skipMessage()
      Reads and discards an entire message.
      void skipRawBytes​(int size)
      Reads and discards size bytes.
      • Methods inherited from class java.io.FilterInputStream

        available, close, mark, markSupported, read, read, read, reset, skip
      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • CodedInputStream

        public CodedInputStream​(java.io.InputStream in)
      • CodedInputStream

        public CodedInputStream​(Buffer data)
      • CodedInputStream

        public CodedInputStream​(byte[] data)
    • Method Detail

      • readTag

        public int readTag()
                    throws java.io.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:
        java.io.IOException
      • checkLastTagWas

        public 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.
      • skipField

        public boolean skipField​(int tag)
                          throws java.io.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:
        java.io.IOException
      • skipMessage

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

        public double readDouble()
                          throws java.io.IOException
        Read a double field value from the stream.
        Throws:
        java.io.IOException
      • readFloat

        public float readFloat()
                        throws java.io.IOException
        Read a float field value from the stream.
        Throws:
        java.io.IOException
      • readUInt64

        public long readUInt64()
                        throws java.io.IOException
        Read a uint64 field value from the stream.
        Throws:
        java.io.IOException
      • readInt64

        public long readInt64()
                       throws java.io.IOException
        Read an int64 field value from the stream.
        Throws:
        java.io.IOException
      • readInt32

        public int readInt32()
                      throws java.io.IOException
        Read an int32 field value from the stream.
        Throws:
        java.io.IOException
      • readFixed64

        public long readFixed64()
                         throws java.io.IOException
        Read a fixed64 field value from the stream.
        Throws:
        java.io.IOException
      • readFixed32

        public int readFixed32()
                        throws java.io.IOException
        Read a fixed32 field value from the stream.
        Throws:
        java.io.IOException
      • readBool

        public boolean readBool()
                         throws java.io.IOException
        Read a bool field value from the stream.
        Throws:
        java.io.IOException
      • readString

        public java.lang.String readString()
                                    throws java.io.IOException
        Read a string field value from the stream.
        Throws:
        java.io.IOException
      • readBytes

        public Buffer readBytes()
                         throws java.io.IOException
        Read a bytes field value from the stream.
        Throws:
        java.io.IOException
      • readUInt32

        public int readUInt32()
                       throws java.io.IOException
        Read a uint32 field value from the stream.
        Throws:
        java.io.IOException
      • readEnum

        public int readEnum()
                     throws java.io.IOException
        Read an enum field value from the stream. Caller is responsible for converting the numeric value to an actual enum.
        Throws:
        java.io.IOException
      • readSFixed32

        public int readSFixed32()
                         throws java.io.IOException
        Read an sfixed32 field value from the stream.
        Throws:
        java.io.IOException
      • readSFixed64

        public long readSFixed64()
                          throws java.io.IOException
        Read an sfixed64 field value from the stream.
        Throws:
        java.io.IOException
      • readSInt32

        public int readSInt32()
                       throws java.io.IOException
        Read an sint32 field value from the stream.
        Throws:
        java.io.IOException
      • readSInt64

        public long readSInt64()
                        throws java.io.IOException
        Read an sint64 field value from the stream.
        Throws:
        java.io.IOException
      • readRawVarint32

        public int readRawVarint32()
                            throws java.io.IOException
        Read a raw Varint from the stream. If larger than 32 bits, discard the upper bits.
        Throws:
        java.io.IOException
      • readRawVarint64

        public long readRawVarint64()
                             throws java.io.IOException
        Read a raw Varint from the stream.
        Throws:
        java.io.IOException
      • readRawLittleEndian32

        public int readRawLittleEndian32()
                                  throws java.io.IOException
        Read a 32-bit little-endian integer from the stream.
        Throws:
        java.io.IOException
      • readRawLittleEndian64

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

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

        public Buffer readRawBytes​(int size)
                            throws java.io.IOException
        Read a fixed size of bytes from the input.
        Throws:
        InvalidProtocolBufferException - The end of the stream or the current limit was reached.
        java.io.IOException
      • skipRawBytes

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

        public int pushLimit​(int limit)
      • popLimit

        public void popLimit​(int limit)