blob: 87e1b7a03e521c78d9835bb1bc090e9bbcf02ad9 [file] [log] [blame]
/**
* @author: Jeff Thompson
* See COPYING for copyright and distribution information.
*/
#ifndef NDN_BINARYXMLDECODER_H
#define NDN_BINARYXMLDECODER_H
#include "../errors.h"
#ifdef __cplusplus
extern "C" {
#endif
struct ndn_BinaryXmlDecoder {
unsigned char *input;
unsigned int inputLength;
unsigned int offset;
};
static inline void ndn_BinaryXmlDecoder_init(struct ndn_BinaryXmlDecoder *self, unsigned char *input, unsigned int inputLength)
{
self->input = input;
self->inputLength = inputLength;
self->offset = 0;
}
/**
* Decode the header's type and value from self's input starting at offset. Update offset.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param type output for the header type
* @param value output for the header value
* @return 0 for success, else an error code for read past the end of the input or if the initial byte is zero
*/
ndn_Error ndn_BinaryXmlDecoder_decodeTypeAndValue(struct ndn_BinaryXmlDecoder *self, unsigned int *type, unsigned int *value);
/**
* Decode the header from self's input starting at offset, expecting the type to be DTAG and the value to be expectedTag.
* Update offset.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @return 0 for success, else an error code, including an error if not the expected tag
*/
ndn_Error ndn_BinaryXmlDecoder_readElementStartDTag(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag);
/**
* Read one byte from self's input starting at offset, expecting it to be the element close.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @return 0 for success, else an error code, including an error if not the element close
*/
ndn_Error ndn_BinaryXmlDecoder_readElementClose(struct ndn_BinaryXmlDecoder *self);
/**
* Decode the header from self's input starting at offset, and if it is a DTAG where the value is the expectedTag,
* then set gotExpectedTag to 1, else 0. Do not update offset, including if returning an error.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param gotExpectedTag output a 1 if got the expected tag, else 0
* @return 0 for success, else an error code for read past the end of the input
*/
ndn_Error ndn_BinaryXmlDecoder_peekDTag(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, int *gotExpectedTag);
/**
* Decode the header from self's input starting at offset, expecting the type to be DTAG and the value to be expectedTag.
* Then read one item of any type (presumably BLOB, UDATA, TAG or ATTR) and return the item's value and length.
* However, if allowNull is 1, then the item may be absent.
* Finally, read the element close. Update offset.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param allowNull 1 if the binary item may be missing
* @param value output a pointer to the binary data inside self's input buffer. However, if allowNull is 1 and the
* binary data item is absent, then return 0.
* @param valueLength output the length of the binary data. However, if allowNull is 1 and the
* binary data item is absent, then return 0.
* @return 0 for success, else an error code, including an error if not the expected tag, or if allowNull is 0
* and the binary data is absent
*/
ndn_Error ndn_BinaryXmlDecoder_readBinaryDTagElement
(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, int allowNull, unsigned char **value, unsigned int *valueLength);
/**
* Peek at the next element and if it is the expectedTag, call ndn_BinaryXmlDecoder_readBinaryDTagElement.
* Otherwise, set value and valueLength to 0.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param allowNull 1 if the binary item may be missing
* @param value output a pointer to the binary data inside self's input buffer. However, if allowNull is 1 and the
* binary data item is absent, then return 0.
* @param valueLength output the length of the binary data. However, if allowNull is 1 and the
* binary data item is absent, then return 0.
* @return 0 for success, else an error code, including if allowNull is 0 and the binary data is absent
*/
ndn_Error ndn_BinaryXmlDecoder_readOptionalBinaryDTagElement
(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, int allowNull, unsigned char **value, unsigned int *valueLength);
/**
* Decode the header from self's input starting at offset, expecting the type to be DTAG and the value to be expectedTag.
* Then read one item expecting it to be type UDATA, and return the item's value and length.
* Finally, read the element close. Update offset.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param value output a pointer to the binary data inside self's input buffer.
* @param valueLength output the length of the binary data.
* @return 0 for success, else an error code, including an error if not the expected tag, or if the item is not UDATA.
*/
ndn_Error ndn_BinaryXmlDecoder_readUDataDTagElement
(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, unsigned char **value, unsigned int *valueLength);
/**
* Decode the header from self's input starting at offset, expecting the type to be DTAG and the value to be expectedTag.
* Then read one item expecting it to be type UDATA, parse it as an unsigned decimal integer and return the integer.
* Finally, read the element close. Update offset.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param value output the unsigned integer
* @return 0 for success, else an error code, including an error if not the expected tag, or if the item is not UDATA,
* or can't parse the integer
*/
ndn_Error ndn_BinaryXmlDecoder_readUnsignedIntegerDTagElement
(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, unsigned int *value);
/**
* Peek at the next element, and if it has the expectedTag then call ndn_BinaryXmlDecoder_readUnsignedIntegerDTagElement.
* Otherwise, set value to -1.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param value output the unsigned integer cast to int, or -1 if the next element doesn't have expectedTag.
* @return 0 for success, else an error code, including an error if the item is not UDATA,
* or can't parse the integer
*/
ndn_Error ndn_BinaryXmlDecoder_readOptionalUnsignedIntegerDTagElement
(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, int *value);
/**
* Decode the header from self's input starting at offset, expecting the type to be DTAG and the value to be expectedTag.
* Then read one item, parse it as an unsigned big endian integer in 4096 ticks per second, and convert it to milliseconds.
* Finally, read the element close. Update offset.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param milliseconds output the number of milliseconds
* @return 0 for success, else an error code, including an error if not the expected tag
*/
ndn_Error ndn_BinaryXmlDecoder_readTimeMillisecondsDTagElement
(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, double *milliseconds);
/**
* Peek at the next element, and if it has the expectedTag then call ndn_BinaryXmlDecoder_readTimeMillisecondsDTagElement.
* Otherwise, set value to -1.0 .
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param expectedTag the expected value for DTAG
* @param milliseconds output the number of milliseconds, or -1.0 if the next element doesn't have expectedTag.
* @return 0 for success, else an error code
*/
ndn_Error ndn_BinaryXmlDecoder_readOptionalTimeMillisecondsDTagElement
(struct ndn_BinaryXmlDecoder *self, unsigned int expectedTag, double *milliseconds);
/**
* Interpret the bytes as an unsigned big endian integer and convert to a double. Don't check for overflow.
* We use a double because it is large enough to represent NDN time (4096 ticks per second since 1970).
* @param bytes pointer to the array of bytes
* @param bytesLength the length of bytes
* @return the result
*/
double ndn_BinaryXmlDecoder_unsignedBigEndianToDouble(unsigned char *bytes, unsigned int bytesLength);
/**
* Set the offset into the input, used for the next read.
* @param self pointer to the ndn_BinaryXmlDecoder struct
* @param offset the new offset
*/
static inline void ndn_BinaryXmlDecoder_seek(struct ndn_BinaryXmlDecoder *self, unsigned int offset)
{
self->offset = offset;
}
#ifdef __cplusplus
}
#endif
#endif