Package io.protostuff
Class CodedInput
java.lang.Object
io.protostuff.CodedInput
- All Implemented Interfaces:
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.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final byte[]
private int
private int
private int
private int
The absolute position of the end of the current message.final boolean
If true, the nested messages are group-encoded(package private) static final int
(package private) static final int
private final InputStream
private int
private int
private int
See setSizeLimit()private int
The total number of bytes read before the current buffer. -
Constructor Summary
ConstructorsConstructorDescriptionCodedInput
(byte[] buffer, int off, int len, boolean decodeNestedMessageAsGroup) CodedInput
(InputStream input, boolean decodeNestedMessageAsGroup) CodedInput
(InputStream input, byte[] buffer, boolean decodeNestedMessageAsGroup) CodedInput
(InputStream input, byte[] buffer, int offset, int limit, boolean decodeNestedMessageAsGroup) -
Method Summary
Modifier and TypeMethodDescriptionprivate void
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
Returns the number of bytes to be read before the current limit.int
Returns the last tag.int
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
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 thegroup
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
(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 thatpushLimit()
does NOT affect how many bytes theCodedInputStream
reads from an underlyingInputStream
when refreshing its buffer.boolean
readBool()
Read abool
field value from the stream.byte[]
Reads a byte array field value.Reads a byte array/ByteBuffer value.Read abytes
field value from the stream.void
readBytes
(ByteBuffer bb) Read astring
field value from the stream into a ByteBuffer.double
Read adouble
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 givenschema
.int
Read afixed32
field value from the stream.long
Read afixed64
field value from the stream.float
Read afloat
field value from the stream.int
Read anint32
field value from the stream.long
Read anint64
field value from the stream.byte
Read one byte from the input.byte[]
readRawBytes
(int size) Read a fixed size of bytes from the input.int
Read a 32-bit little-endian integer from the stream.long
Read a 64-bit little-endian integer from the stream.int
Read a raw Varint from the stream.(package private) static int
readRawVarint32
(DataInput input, byte firstByte) Reads a varint from the input one byte at a time from aDataInput
, so that it does not read any bytes after the end of the varint.(package private) static int
readRawVarint32
(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
(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
Read a raw Varint from the stream.int
Read ansfixed32
field value from the stream.long
Read ansfixed64
field value from the stream.int
Read ansint32
field value from the stream.long
Read ansint64
field value from the stream.Read astring
field value from the stream.int
readTag()
Attempt to read a field tag, returning zero if we have reached EOF.int
Read auint32
field value from the stream.long
Read auint64
field value from the stream.private void
private boolean
refillBuffer
(boolean mustSucceed) Called withthis.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
Resets the current size counter to zero (seesetSizeLimit(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
Reads and discards an entire message.void
skipRawBytes
(int size) Reads and discardssize
bytes.void
transferByteRangeTo
(Output output, boolean utf8String, int fieldNumber, boolean repeated) Transfer the byte range to the output.
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Field Details
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buffer
private final byte[] buffer -
bufferSize
private int bufferSize -
bufferSizeAfterLimit
private int bufferSizeAfterLimit -
bufferPos
private int bufferPos -
input
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lastTag
private int lastTag -
packedLimit
private int packedLimit -
totalBytesRetired
private int totalBytesRetiredThe total number of bytes read before the current buffer. The total bytes read up to the current position can be computed astotalBytesRetired + 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 currentLimitThe absolute position of the end of the current message. -
decodeNestedMessageAsGroup
public final boolean decodeNestedMessageAsGroupIf true, the nested messages are group-encoded -
sizeLimit
private int sizeLimitSee setSizeLimit() -
DEFAULT_SIZE_LIMIT
static final int DEFAULT_SIZE_LIMIT- See Also:
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DEFAULT_BUFFER_SIZE
static final int DEFAULT_BUFFER_SIZE- See Also:
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Constructor Details
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CodedInput
public CodedInput(byte[] buffer, int off, int len, boolean decodeNestedMessageAsGroup) -
CodedInput
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CodedInput
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CodedInput
public CodedInput(InputStream input, byte[] buffer, int offset, int limit, boolean decodeNestedMessageAsGroup)
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Method Details
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newInstance
Create a new CodedInput wrapping the given InputStream. -
newInstance
Create a new CodedInput wrapping the given byte array. -
newInstance
Create a new CodedInput wrapping the given byte array slice. -
readTag
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
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checkLastTagWas
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.
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skipField
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, returnstrue
.- Throws:
IOException
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skipMessage
Reads and discards an entire message. This will read either until EOF or until an endgroup tag, whichever comes first.- Throws:
IOException
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readDouble
Read adouble
field value from the stream.- Specified by:
readDouble
in interfaceInput
- Throws:
IOException
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readFloat
Read afloat
field value from the stream.- Specified by:
readFloat
in interfaceInput
- Throws:
IOException
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readUInt64
Read auint64
field value from the stream.- Specified by:
readUInt64
in interfaceInput
- Throws:
IOException
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readInt64
Read anint64
field value from the stream.- Specified by:
readInt64
in interfaceInput
- Throws:
IOException
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readInt32
Read anint32
field value from the stream.- Specified by:
readInt32
in interfaceInput
- Throws:
IOException
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readFixed64
Read afixed64
field value from the stream.- Specified by:
readFixed64
in interfaceInput
- Throws:
IOException
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readFixed32
Read afixed32
field value from the stream.- Specified by:
readFixed32
in interfaceInput
- Throws:
IOException
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readBool
Read abool
field value from the stream.- Specified by:
readBool
in interfaceInput
- Throws:
IOException
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readString
Read astring
field value from the stream.- Specified by:
readString
in interfaceInput
- Throws:
IOException
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readBytes
Read astring
field value from the stream into a ByteBuffer.- Specified by:
readBytes
in interfaceInput
- Throws:
IOException
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mergeObject
Description copied from interface:Input
Merges an object(with schema) field value. The providedschema
handles the deserialization for the object.- Specified by:
mergeObject
in interfaceInput
- Throws:
IOException
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mergeObjectEncodedAsGroup
Reads a message field value from the stream (using thegroup
encoding).- Throws:
IOException
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readBytes
Read abytes
field value from the stream.- Specified by:
readBytes
in interfaceInput
- Throws:
IOException
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readUInt32
Read auint32
field value from the stream.- Specified by:
readUInt32
in interfaceInput
- Throws:
IOException
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readEnum
Read an enum field value from the stream. Caller is responsible for converting the numeric value to an actual enum.- Specified by:
readEnum
in interfaceInput
- Throws:
IOException
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readSFixed32
Read ansfixed32
field value from the stream.- Specified by:
readSFixed32
in interfaceInput
- Throws:
IOException
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readSFixed64
Read ansfixed64
field value from the stream.- Specified by:
readSFixed64
in interfaceInput
- Throws:
IOException
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readSInt32
Read ansint32
field value from the stream.- Specified by:
readSInt32
in interfaceInput
- Throws:
IOException
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readSInt64
Read ansint64
field value from the stream.- Specified by:
readSInt64
in interfaceInput
- Throws:
IOException
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readRawVarint32
Read a raw Varint from the stream. If larger than 32 bits, discard the upper bits.- Throws:
IOException
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readRawVarint32
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 usedreadRawVarint32(InputStream)
then you would probably end up reading past the end of the varint since CodedInput buffers its input.- Throws:
IOException
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readRawVarint32
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 usedreadRawVarint32(InputStream)
then you would probably end up reading past the end of the varint since CodedInput buffers its input.- Throws:
IOException
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readRawVarint32
Reads a varint from the input one byte at a time from aDataInput
, so that it does not read any bytes after the end of the varint.- Throws:
IOException
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readRawVarint64
Read a raw Varint from the stream.- Throws:
IOException
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readRawLittleEndian32
Read a 32-bit little-endian integer from the stream.- Throws:
IOException
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readRawLittleEndian64
Read a 64-bit little-endian integer from the stream.- Throws:
IOException
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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.
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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.
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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 anInputStream
, 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.
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resetSizeCounter
public void resetSizeCounter()Resets the current size counter to zero (seesetSizeLimit(int)
). The fieldtotalBytesRetired
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
Note thatpushLimit()
does NOT affect how many bytes theCodedInputStream
reads from an underlyingInputStream
when refreshing its buffer. If you need to prevent reading past a certain point in the underlyingInputStream
(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 yourInputStream
which limits the amount of data that can be read from it.- Returns:
- the old limit.
- Throws:
ProtobufException
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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 bypushLimit
.
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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
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 usingpushLimit(int)
.- Throws:
IOException
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getTotalBytesRead
public int getTotalBytesRead()The total bytes read up to the current position. CallingresetSizeCounter()
resets this value to zero. -
refillBuffer
Called withthis.buffer
is empty to read more bytes from the input. IfmustSucceed
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. IfmustSucceed
is false, refillBuffer() returns false if no more bytes were available.- Throws:
IOException
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readRawByte
Read one byte from the input.- Throws:
ProtobufException
- The end of the stream or the current limit was reached.IOException
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readRawBytes
Read a fixed size of bytes from the input.- Throws:
ProtobufException
- The end of the stream or the current limit was reached.IOException
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skipRawBytes
Reads and discardssize
bytes.- Throws:
ProtobufException
- The end of the stream or the current limit was reached.IOException
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readFieldNumber
Description copied from interface:Input
Reads the field number of a message/object tied to the givenschema
.- Specified by:
readFieldNumber
in interfaceInput
- Throws:
IOException
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checkIfPackedField
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:
IOException
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readByteArray
Description copied from interface:Input
Reads a byte array field value.- Specified by:
readByteArray
in interfaceInput
- Throws:
IOException
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handleUnknownField
Description copied from interface:Input
The underlying implementation should handle the unknown field.- Specified by:
handleUnknownField
in interfaceInput
- Throws:
IOException
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transferByteRangeTo
public void transferByteRangeTo(Output output, boolean utf8String, int fieldNumber, boolean repeated) throws 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 interfaceInput
- Throws:
IOException
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getLastTag
public int getLastTag()Returns the last tag. -
readByteBuffer
Reads a byte array/ByteBuffer value.- Specified by:
readByteBuffer
in interfaceInput
- Throws:
IOException
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