Package io.protostuff

Class CodedInput

  • All Implemented Interfaces:
    Input

    public final class CodedInput
    extends java.lang.Object
    implements Input
    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.

    • Constructor Summary

      Constructors 
      Constructor Description
      CodedInput​(byte[] buffer, int off, int len, boolean decodeNestedMessageAsGroup)  
      CodedInput​(java.io.InputStream input, boolean decodeNestedMessageAsGroup)  
      CodedInput​(java.io.InputStream input, byte[] buffer, boolean decodeNestedMessageAsGroup)  
      CodedInput​(java.io.InputStream input, byte[] buffer, int offset, int limit, boolean decodeNestedMessageAsGroup)  
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private void checkIfPackedField()
      Check if this field have been packed into a length-delimited field.
      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.
      int getBytesUntilLimit()
      Returns the number of bytes to be read before the current limit.
      int getLastTag()
      Returns the last tag.
      int getTotalBytesRead()
      The total bytes read up to the current position.
      <T> void handleUnknownField​(int fieldNumber, Schema<T> schema)
      The underlying implementation should handle the unknown field.
      boolean isAtEnd()
      Returns true if the stream has reached the end of the input.
      boolean isCurrentFieldPacked()
      Return true if currently reading packed field
      <T> T mergeObject​(T value, Schema<T> schema)
      Merges an object(with schema) field value.
      private <T> T mergeObjectEncodedAsGroup​(T value, Schema<T> schema)
      Reads a message field value from the stream (using the group encoding).
      static CodedInput newInstance​(byte[] buf)
      Create a new CodedInput wrapping the given byte array.
      static CodedInput newInstance​(byte[] buf, int off, int len)
      Create a new CodedInput wrapping the given byte array slice.
      static CodedInput newInstance​(java.io.InputStream input)
      Create a new CodedInput wrapping the given InputStream.
      void popLimit​(int oldLimit)
      Discards the current limit, returning to the previous limit.
      int pushLimit​(int byteLimit)
      Note that pushLimit() does NOT affect how many bytes the CodedInputStream reads from an underlying InputStream when refreshing its buffer.
      boolean readBool()
      Read a bool field value from the stream.
      byte[] readByteArray()
      Reads a byte array field value.
      java.nio.ByteBuffer readByteBuffer()
      Reads a byte array/ByteBuffer value.
      ByteString readBytes()
      Read a bytes field value from the stream.
      void readBytes​(java.nio.ByteBuffer bb)
      Read a string field value from the stream into a ByteBuffer.
      double readDouble()
      Read a double field value from the stream.
      int readEnum()
      Read an enum field value from the stream.
      <T> int readFieldNumber​(Schema<T> schema)
      Reads the field number of a message/object tied to the given schema.
      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.
      byte[] 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.
      (package private) static int readRawVarint32​(java.io.DataInput input, byte firstByte)
      Reads a varint from the input one byte at a time from a DataInput, so that it does not read any bytes after the end of the varint.
      (package private) static int readRawVarint32​(java.io.InputStream input)
      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.
      (package private) static int readRawVarint32​(java.io.InputStream input, int firstByte)
      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.
      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.
      private void recomputeBufferSizeAfterLimit()  
      private boolean refillBuffer​(boolean mustSucceed)
      Called with this.buffer is empty to read more bytes from the input.
      void reset()
      Resets the buffer position and limit to re-use this CodedInput object.
      void resetSizeCounter()
      Resets the current size counter to zero (see setSizeLimit(int)).
      int setSizeLimit​(int limit)
      Set the maximum message size.
      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.
      void transferByteRangeTo​(Output output, boolean utf8String, int fieldNumber, boolean repeated)
      Transfer the byte range to the output.
      • Methods inherited from class java.lang.Object

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

      • buffer

        private final byte[] buffer
      • bufferSize

        private int bufferSize
      • bufferSizeAfterLimit

        private int bufferSizeAfterLimit
      • bufferPos

        private int bufferPos
      • input

        private final java.io.InputStream input
      • lastTag

        private int lastTag
      • packedLimit

        private int packedLimit
      • totalBytesRetired

        private int totalBytesRetired
        The total number of bytes read before the current buffer. The total bytes read up to the current position can be computed as 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).
      • currentLimit

        private int currentLimit
        The absolute position of the end of the current message.
      • decodeNestedMessageAsGroup

        public final boolean decodeNestedMessageAsGroup
        If true, the nested messages are group-encoded
      • sizeLimit

        private int sizeLimit
        See setSizeLimit()
    • Constructor Detail

      • CodedInput

        public CodedInput​(byte[] buffer,
                          int off,
                          int len,
                          boolean decodeNestedMessageAsGroup)
      • CodedInput

        public CodedInput​(java.io.InputStream input,
                          boolean decodeNestedMessageAsGroup)
      • CodedInput

        public CodedInput​(java.io.InputStream input,
                          byte[] buffer,
                          boolean decodeNestedMessageAsGroup)
      • CodedInput

        public CodedInput​(java.io.InputStream input,
                          byte[] buffer,
                          int offset,
                          int limit,
                          boolean decodeNestedMessageAsGroup)
    • Method Detail

      • newInstance

        public static CodedInput newInstance​(java.io.InputStream input)
        Create a new CodedInput wrapping the given InputStream.
      • newInstance

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

        public static CodedInput newInstance​(byte[] buf,
                                             int off,
                                             int len)
        Create a new CodedInput wrapping the given byte array slice.
      • 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 ProtobufException
        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:
        ProtobufException - 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.
        Specified by:
        readDouble in interface Input
        Throws:
        java.io.IOException
      • readFloat

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

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

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

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

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

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

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

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

        public void readBytes​(java.nio.ByteBuffer bb)
                       throws java.io.IOException
        Read a string field value from the stream into a ByteBuffer.
        Specified by:
        readBytes in interface Input
        Throws:
        java.io.IOException
      • mergeObject

        public <T> T mergeObject​(T value,
                                 Schema<T> schema)
                          throws java.io.IOException
        Description copied from interface: Input
        Merges an object(with schema) field value. The provided schema handles the deserialization for the object.
        Specified by:
        mergeObject in interface Input
        Throws:
        java.io.IOException
      • mergeObjectEncodedAsGroup

        private <T> T mergeObjectEncodedAsGroup​(T value,
                                                Schema<T> schema)
                                         throws java.io.IOException
        Reads a message field value from the stream (using the group encoding).
        Throws:
        java.io.IOException
      • readBytes

        public ByteString readBytes()
                             throws java.io.IOException
        Read a bytes field value from the stream.
        Specified by:
        readBytes in interface Input
        Throws:
        java.io.IOException
      • readUInt32

        public int readUInt32()
                       throws java.io.IOException
        Read a uint32 field value from the stream.
        Specified by:
        readUInt32 in interface Input
        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.
        Specified by:
        readEnum in interface Input
        Throws:
        java.io.IOException
      • readSFixed32

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

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

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

        public long readSInt64()
                        throws java.io.IOException
        Read an sint64 field value from the stream.
        Specified by:
        readSInt64 in interface Input
        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
      • readRawVarint32

        static int readRawVarint32​(java.io.InputStream input)
                            throws java.io.IOException
        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 CodedInput and used readRawVarint32(InputStream) then you would probably end up reading past the end of the varint since CodedInput buffers its input.
        Throws:
        java.io.IOException
      • readRawVarint32

        static int readRawVarint32​(java.io.InputStream input,
                                   int firstByte)
                            throws java.io.IOException
        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 CodedInput and used readRawVarint32(InputStream) then you would probably end up reading past the end of the varint since CodedInput buffers its input.
        Throws:
        java.io.IOException
      • readRawVarint32

        static int readRawVarint32​(java.io.DataInput input,
                                   byte firstByte)
                            throws java.io.IOException
        Reads a varint from the input one byte at a time from a DataInput, so that it does not read any bytes after the end of the varint.
        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.
      • setSizeLimit

        public int setSizeLimit​(int limit)
        Set the maximum message size. In order to prevent malicious messages from exhausting memory or causing integer overflows, CodedInput 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 InputStream, not when constructed around a raw byte array.

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

        Returns:
        the old limit.
      • resetSizeCounter

        public void resetSizeCounter()
        Resets the current size counter to zero (see setSizeLimit(int)). The field totalBytesRetired will be negative if the initial position was not zero.
      • reset

        public void reset()
        Resets the buffer position and limit to re-use this CodedInput object.
      • pushLimit

        public int pushLimit​(int byteLimit)
                      throws ProtobufException
        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:
        ProtobufException
      • recomputeBufferSizeAfterLimit

        private void recomputeBufferSizeAfterLimit()
      • popLimit

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

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

        public boolean isCurrentFieldPacked()
        Return true if currently reading packed field
      • isAtEnd

        public boolean isAtEnd()
                        throws java.io.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).
        Throws:
        java.io.IOException
      • getTotalBytesRead

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

        private boolean refillBuffer​(boolean mustSucceed)
                              throws java.io.IOException
        Called with this.buffer is empty to read more bytes from the input. If mustSucceed is true, refillBuffer() guarantees that either there will be at least one byte in the buffer when it returns or it will throw an exception. If mustSucceed is false, refillBuffer() returns false if no more bytes were available.
        Throws:
        java.io.IOException
      • readRawByte

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

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

        public <T> int readFieldNumber​(Schema<T> schema)
                                throws java.io.IOException
        Description copied from interface: Input
        Reads the field number of a message/object tied to the given schema.
        Specified by:
        readFieldNumber in interface Input
        Throws:
        java.io.IOException
      • checkIfPackedField

        private void checkIfPackedField()
                                 throws java.io.IOException
        Check if this field have been packed into a length-delimited field. If so, update internal state to reflect that packed fields are being read.
        Throws:
        java.io.IOException
      • readByteArray

        public byte[] readByteArray()
                             throws java.io.IOException
        Description copied from interface: Input
        Reads a byte array field value.
        Specified by:
        readByteArray in interface Input
        Throws:
        java.io.IOException
      • handleUnknownField

        public <T> void handleUnknownField​(int fieldNumber,
                                           Schema<T> schema)
                                    throws java.io.IOException
        Description copied from interface: Input
        The underlying implementation should handle the unknown field.
        Specified by:
        handleUnknownField in interface Input
        Throws:
        java.io.IOException
      • transferByteRangeTo

        public void transferByteRangeTo​(Output output,
                                        boolean utf8String,
                                        int fieldNumber,
                                        boolean repeated)
                                 throws java.io.IOException
        Description copied from interface: Input
        Transfer the byte range to the output. Capable of zero-copy transfer depending on the type of input.
        Specified by:
        transferByteRangeTo in interface Input
        Throws:
        java.io.IOException
      • getLastTag

        public int getLastTag()
        Returns the last tag.
      • readByteBuffer

        public java.nio.ByteBuffer readByteBuffer()
                                           throws java.io.IOException
        Reads a byte array/ByteBuffer value.
        Specified by:
        readByteBuffer in interface Input
        Throws:
        java.io.IOException