NAME

src/packfile/pf_items.c - Fetch/store packfile data

DESCRIPTION

Low level packfile functions to fetch and store Parrot data, i.e. INTVAL, FLOATVAL, STRING ...

PF_fetch_<item>() functions retrieve the datatype item from the opcode stream and convert byteordering or binary format on the fly, depending on the packfile header.

PF_store_<item>() functions write the datatype item to the stream as is. These functions don't check the available size.

PF_size_<item>() functions return the store size of item in opcode_t units.

BE and be are short for "Big-endian", while LE and le are short for "little endian".

Functions

static void cvt_num12_num8: Converts i386 LE 12-byte long double to IEEE 754 8 byte double
static void cvt_num12_num8_be: Converts a 12-byte i386 long double into a big-endian IEEE 754 8-byte double. converting to BE not yet implemented (throws internal_exception).
static void cvt_num12_num8_le: Converts a 12-byte i386 long double into a little-endian IEEE 754 8-byte double.
static opcode_t fetch_op_test: Fetches an opcode_t operation in little-endian format.
static opcode_t fetch_op_mixed_le: opcode fetch helper function; This is mostly wrong or at least untested; Fetch an opcode and convert to LE
static opcode_t fetch_op_mixed_be: Fetch an opcode and convert to BE. Determines size of opcode from OPCODE_T_SIZE macro, and proceeds accordingly.
static opcode_t fetch_op_be_4: Fetches a 4-byte big-endian opcode.
static opcode_t fetch_op_be_8: Fetches an 8-byte big-endian opcode.
static opcode_t fetch_op_le_4: Fetches a 4-byte little-endian opcode
static opcode_t fetch_op_le_8: Fetches an 8-byte little-endian opcode
opcode_t PF_fetch_opcode: Fetches an opcode_t from the stream, converting byteorder if needed.
opcode_t *PF_store_opcode: Stores an opcode_t to stream as-is.
size_t PF_size_opcode: Returns the size of an item in opcode_t units. The size of opcode_t is 1 per definition.
INTVAL PF_fetch_integer: Fetches an INTVAL from the stream, converting byteorder if needed.; XXX assumes sizeof (INTVAL) == sizeof (opcode_t) - we don't have INTVAL size in the PackFile header.
opcode_t *PF_store_integer: Stores an INTVAL to stream as is.
size_t PF_size_integer: Returns stored size of INTVAL in opcode_t units.
FLOATVAL PF_fetch_number: Fetches a FLOATVAL from the stream, converting byteorder if needed. Then advances the stream pointer by the packfile float size.
opcode_t *PF_store_number: Writes a FLOATVAL to the opcode stream as-is.
size_t PF_size_number: Returns stored size of FLOATVAL in opcode_t units.
STRING *PF_fetch_string: Fetches a STRING from bytecode and return a new STRING.; Opcode format is:
opcode_t *PF_store_string: Writes a STRING to the opcode stream.
size_t PF_size_string: Reports stored size of STRING in opcode_t units.
char *PF_fetch_cstring: Fetches a cstring from bytecode and returns an allocated copy
opcode_t *PF_store_cstring: Writes a NULL-terminated string to the stream.
size_t PF_size_cstring: Returns store size of a C-string in opcode_t units.
void PackFile_assign_transforms: Assigns transform functions to the vtable.

HISTORY

Initial review by leo 2003.11.21

Most routines moved from src/packfile.c.

Renamed PackFile_* to PF_*

TODO

<PF_store_<type()>> - write an opcode_t stream to cursor in natural byte-ordering.

<PF_fetch_<type()>> - read items and possibly convert the foreign format.

<PF_size_<type()>> - return the needed size in opcode_t units.