org.apache.activemq.protobuf
Class CodedInputStream

java.lang.Object
  extended by java.io.InputStream
      extended by java.io.FilterInputStream
          extended by org.apache.activemq.protobuf.CodedInputStream
All Implemented Interfaces:
java.io.Closeable

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
 
Constructor Summary
CodedInputStream(Buffer data)
           
CodedInputStream(byte[] data)
           
CodedInputStream(java.io.InputStream in)
           
 
Method Summary
 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.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)


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