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


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 flags
    opcode_t encoding
    opcode_t type
    opcode_t size
    * data
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.


Initial review by leo 2003.11.21

Most routines moved from src/packfile.c.

Renamed PackFile_* to PF_*


<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.