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 functionThis is mostly wrong or at least untestedFetch 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.

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.


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