org.apache.coyote.ajp

Class AjpMessage

public class AjpMessage extends Object

A single packet for communication between the web server and the container. Designed to be reused many times with no creation of garbage. Understands the format of data types for these packets. Can be used (somewhat confusingly) for both incoming and outgoing packets.

Author: Henri Gomez Dan Milstein Keith Wannamaker Kevin Seguin Costin Manolache

Field Summary
protected byte[]buf
Fixed size buffer.
protected intlen
This actually means different things depending on whether the packet is read or write.
protected static Loglog
protected intpos
The current read or write position in the buffer.
protected static StringManagersm
The string manager for this package.
Constructor Summary
AjpMessage(int packetSize)
Method Summary
voidappendByte(int val)
Append a byte (1 byte) to the message.
voidappendByteChunk(ByteChunk bc)
Write a ByteChunk out at the current write position.
voidappendBytes(MessageBytes mb)
Write a MessageBytes out at the current write position.
voidappendBytes(byte[] b, int off, int numBytes)
Copy a chunk of bytes into the packet, starting at the current write position.
voidappendCharChunk(CharChunk cc)
Write a CharChunk out at the current write position.
voidappendInt(int val)
Add a short integer (2 bytes) to the message.
voidappendLongInt(int val)
Append an int (4 bytes) to the message.
voidappendString(String str)
Write a String out at the current write position.
voiddump(String msg)
Dump the contents of the message, prefixed with the given String.
voidend()
For a packet to be sent to the web server, finish the process of accumulating data and write the length of the data payload into the header.
byte[]getBuffer()
Return the underlying byte buffer.
bytegetByte()
voidgetBytes(MessageBytes mb)
intgetBytes(byte[] dest)
Copy a chunk of bytes from the packet into an array and advance the read position past the chunk.
intgetHeaderLength()
intgetInt()
Read an integer from packet, and advance the read position past it.
intgetLen()
Return the current message length.
intgetLongInt()
Read a 32 bits integer from packet, and advance the read position past it.
intgetPacketSize()
protected static Stringhex(int x)
protected static StringhexLine(byte[] buf, int start, int len)
bytepeekByte()
intpeekInt()
intprocessHeader()
voidreset()
Prepare this packet for accumulating a message from the container to the web server.

Field Detail

buf

protected byte[] buf
Fixed size buffer.

len

protected int len
This actually means different things depending on whether the packet is read or write. For read, it's the length of the payload (excluding the header). For write, it's the length of the packet as a whole (counting the header). Oh, well.

log

protected static Log log

pos

protected int pos
The current read or write position in the buffer.

sm

protected static StringManager sm
The string manager for this package.

Constructor Detail

AjpMessage

public AjpMessage(int packetSize)

Method Detail

appendByte

public void appendByte(int val)
Append a byte (1 byte) to the message.

appendByteChunk

public void appendByteChunk(ByteChunk bc)
Write a ByteChunk out at the current write position. A null ByteChunk is encoded as a string with length 0.

appendBytes

public void appendBytes(MessageBytes mb)
Write a MessageBytes out at the current write position. A null MessageBytes is encoded as a string with length 0.

appendBytes

public void appendBytes(byte[] b, int off, int numBytes)
Copy a chunk of bytes into the packet, starting at the current write position. The chunk of bytes is encoded with the length in two bytes first, then the data itself, and finally a terminating \0 (which is not included in the encoded length).

Parameters: b The array from which to copy bytes. off The offset into the array at which to start copying numBytes The number of bytes to copy.

appendCharChunk

public void appendCharChunk(CharChunk cc)
Write a CharChunk out at the current write position. A null CharChunk is encoded as a string with length 0.

appendInt

public void appendInt(int val)
Add a short integer (2 bytes) to the message.

appendLongInt

public void appendLongInt(int val)
Append an int (4 bytes) to the message.

appendString

public void appendString(String str)
Write a String out at the current write position. Strings are encoded with the length in two bytes first, then the string, and then a terminating \0 (which is not included in the encoded length). The terminator is for the convenience of the C code, where it saves a round of copying. A null string is encoded as a string with length 0.

dump

public void dump(String msg)
Dump the contents of the message, prefixed with the given String.

end

public void end()
For a packet to be sent to the web server, finish the process of accumulating data and write the length of the data payload into the header.

getBuffer

public byte[] getBuffer()
Return the underlying byte buffer.

getByte

public byte getByte()

getBytes

public void getBytes(MessageBytes mb)

getBytes

public int getBytes(byte[] dest)
Copy a chunk of bytes from the packet into an array and advance the read position past the chunk. See appendBytes() for details on the encoding.

Returns: The number of bytes copied.

getHeaderLength

public int getHeaderLength()

getInt

public int getInt()
Read an integer from packet, and advance the read position past it. Integers are encoded as two unsigned bytes with the high-order byte first, and, as far as I can tell, in little-endian order within each byte.

getLen

public int getLen()
Return the current message length. For read, it's the length of the payload (excluding the header). For write, it's the length of the packet as a whole (counting the header).

getLongInt

public int getLongInt()
Read a 32 bits integer from packet, and advance the read position past it. Integers are encoded as four unsigned bytes with the high-order byte first, and, as far as I can tell, in little-endian order within each byte.

getPacketSize

public int getPacketSize()

hex

protected static String hex(int x)

hexLine

protected static String hexLine(byte[] buf, int start, int len)

peekByte

public byte peekByte()

peekInt

public int peekInt()

processHeader

public int processHeader()

reset

public void reset()
Prepare this packet for accumulating a message from the container to the web server. Set the write position to just after the header (but leave the length unwritten, because it is as yet unknown).
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