Methods and apparatus, including computer program products, implementing techniques for encoding binary XML. The techniques include receiving data to be encoded and encoding the data as binary XML data. The binary XML data includes one or more elements. Each element is represented by an index number that identifies the element, a length number that indicates the length of the element's name, and token numbers that represent tags delimiting the element. The index numbers, length numbers, and token numbers are encoded as a sequence of bytes including at least one byte that represents a composite number. A composite number is a token number combined with either an index number or length number.
1. A computer program product tangibly embodied in a computer-readable storage medium, the computer program product comprising instructions operable to cause a data processing apparatus to perform operations comprising:
receiving data to be encoded;
encoding the data as binary XML data, the binary XML data including one or more elements, wherein each element is represented by an index number that identifies the element, a length number that indicates the length of the element's name, and token numbers that represent tags delimiting the element, and wherein the index numbers, length numbers, and token numbers are encoded as a sequence of bytes including at least one byte that represents a composite number, a composite number being a token number combined with either an index number or length number; and
transmitting the binary XML data.
2. The product of claim 1 , wherein the token numbers are encoded as binary numbers of variable length.
3. The product of claim 1 , wherein encoding the textual data as binary XML data includes representing two or more tags using a single token number.
4. The product of claim 1 , wherein encoding the textual data as binary XML data includes representing an end tag of a first element followed by a start tag of a second element using a single token number.
5. The product of claim 1 , wherein encoding the textual data as binary XML data includes representing each element by a length number that corresponds to the number of characters in the element's name.
6. The product of claim 1 , wherein for each byte, the highest bit is reserved as a continuation bit that indicates whether or not the encoding stored in the byte continues into another byte.
7. A computer program product tangibly embodied in a computer-readable storage medium, the computer program product comprising instructions operable to cause a data processing apparatus to perform operations comprising:
receiving textual data encoded as a binary XML data, the binary XML data including one or more elements, wherein each element is represented by an index number that identifies the element, a length number that indicates the number of characters in the element's name, and token numbers that represent tags delimiting the element, and wherein the index numbers, length numbers, and token numbers are encoded as a sequence of bytes including at least one byte that represents a token number combined with either an index number or length number;
decoding the binary XML data to reveal the textual data, including decoding the at least one byte into two numbers, a token number and either a length number or index number; and
using the length numbers to determine the amount of buffer space to allocate for the element names.
8. The product of claim 7 , wherein the token numbers are encoded as binary numbers of variable length.
9. The product of claim 7 , wherein encoding the textual data as binary XML data includes representing two or more tags using a single token number.
10. The product of claim 7 , wherein encoding the textual data as binary XML data includes representing an end tag of a first element followed by a start tag of a second element using a single token number.
11. The product of claim 7 , wherein encoding the textual data as binary XML data includes representing each element by a length number that corresponds to the number of characters in the element's name.
12. The product of claim 7 , wherein for each byte, the highest bit is reserved as a continuation bit that indicates whether or not the encoding stored in the byte continues into another byte.
13. The product of claim 7 , further comprising:
storing the textual data in memory and using the length numbers to determine how much memory to allocate for the element names.
14. An apparatus comprising:
means for receiving data to be encoded;
means for encoding the data as binary XML data, the binary XML data including one or more elements, wherein each element is represented by an index number that identifies the element, a length number that indicates the length of the element's name, and token numbers that represent tags delimiting the element, and wherein the index numbers, length numbers, and token numbers are encoded as a sequence of bytes including at least one byte that represents a composite number, a composite number being a token number combined with either an index number or length number; and
means for transmitting the binary XML data.
15. An apparatus comprising:
means for receiving textual data encoded as a binary XML data, the binary XML data including one or more elements, wherein each element is represented by an index number that identifies the element, a length number that indicates the number of characters in the element's name, and token numbers that represent tags delimiting the element, and wherein the index numbers, length numbers, and token numbers are encoded as a sequence of bytes including at least one byte that represents a token number combined with either an index number or length number;
means for decoding the binary XML data to reveal the textual data, including decoding the at least one byte into two numbers, a token number and either a length number or index number; and
means for using the length numbers to determine the amount of buffer space to allocate for the element names.