nulib2/nufxlib/ArchiveIO.c
Andy McFadden 9666ebd97a Move method return type to declaration line
Having the method name up against the left edge used to be common
practice, because you could jump to a method quickly by searching
for "^name".  Now we have "ctags" and IDEs.
2014-12-22 16:00:33 -08:00

404 lines
9.6 KiB
C

/*
* NuFX archive manipulation library
* Copyright (C) 2000-2007 by Andy McFadden, All Rights Reserved.
* This is free software; you can redistribute it and/or modify it under the
* terms of the BSD License, see the file COPYING-LIB.
*
* Functions for reading from and writing to the archive. These are
* specialized functions that deal with byte ordering and CRC computation.
* The functions associated with reading from an archive work equally well
* with streaming archives.
*/
#include "NufxLibPriv.h"
/* this makes valgrind and purify happy, at some tiny cost in speed */
#define CLEAN_INIT =0
/*#define CLEAN_INIT */
/*
* ===========================================================================
* Read and write
* ===========================================================================
*/
/*
* Read one byte, optionally computing a CRC.
*/
uint8_t Nu_ReadOneC(NuArchive* pArchive, FILE* fp, uint16_t* pCrc)
{
int ic;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
return (uint8_t) ic;
}
uint8_t Nu_ReadOne(NuArchive* pArchive, FILE* fp)
{
uint16_t dummyCrc CLEAN_INIT;
return Nu_ReadOneC(pArchive, fp, &dummyCrc);
}
/*
* Write one byte, optionally computing a CRC.
*/
void Nu_WriteOneC(NuArchive* pArchive, FILE* fp, uint8_t val, uint16_t* pCrc)
{
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
putc(val, fp);
}
void Nu_WriteOne(NuArchive* pArchive, FILE* fp, uint8_t val)
{
uint16_t dummyCrc CLEAN_INIT;
Nu_WriteOneC(pArchive, fp, val, &dummyCrc);
}
/*
* Read two little-endian bytes, optionally computing a CRC.
*/
uint16_t Nu_ReadTwoC(NuArchive* pArchive, FILE* fp, uint16_t* pCrc)
{
int ic1, ic2;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
ic1 = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic1, *pCrc);
ic2 = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic2, *pCrc);
return ic1 | ic2 << 8;
}
uint16_t Nu_ReadTwo(NuArchive* pArchive, FILE* fp)
{
uint16_t dummyCrc CLEAN_INIT;
return Nu_ReadTwoC(pArchive, fp, &dummyCrc);
}
/*
* Write two little-endian bytes, optionally computing a CRC.
*/
void Nu_WriteTwoC(NuArchive* pArchive, FILE* fp, uint16_t val, uint16_t* pCrc)
{
int ic1, ic2;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
ic1 = val & 0xff;
*pCrc = Nu_UpdateCRC16((uint8_t)ic1, *pCrc);
ic2 = val >> 8;
*pCrc = Nu_UpdateCRC16((uint8_t)ic2, *pCrc);
putc(ic1, fp);
putc(ic2, fp);
}
void Nu_WriteTwo(NuArchive* pArchive, FILE* fp, uint16_t val)
{
uint16_t dummyCrc CLEAN_INIT;
Nu_WriteTwoC(pArchive, fp, val, &dummyCrc);
}
/*
* Read four little-endian bytes, optionally computing a CRC.
*/
uint32_t Nu_ReadFourC(NuArchive* pArchive, FILE* fp, uint16_t* pCrc)
{
int ic1, ic2, ic3, ic4;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
ic1 = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic1, *pCrc);
ic2 = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic2, *pCrc);
ic3 = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic3, *pCrc);
ic4 = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic4, *pCrc);
return ic1 | ic2 << 8 | (uint32_t)ic3 << 16 | (uint32_t)ic4 << 24;
}
uint32_t Nu_ReadFour(NuArchive* pArchive, FILE* fp)
{
uint16_t dummyCrc CLEAN_INIT;
return Nu_ReadFourC(pArchive, fp, &dummyCrc);
}
/*
* Write four little-endian bytes, optionally computing a CRC.
*/
void Nu_WriteFourC(NuArchive* pArchive, FILE* fp, uint32_t val, uint16_t* pCrc)
{
int ic1, ic2, ic3, ic4;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
ic1 = val & 0xff;
*pCrc = Nu_UpdateCRC16((uint8_t)ic1, *pCrc);
ic2 = (val >> 8) & 0xff;
*pCrc = Nu_UpdateCRC16((uint8_t)ic2, *pCrc);
ic3 = (val >> 16) & 0xff;
*pCrc = Nu_UpdateCRC16((uint8_t)ic3, *pCrc);
ic4 = val >> 24;
*pCrc = Nu_UpdateCRC16((uint8_t)ic4, *pCrc);
putc(ic1, fp);
putc(ic2, fp);
putc(ic3, fp);
putc(ic4, fp);
}
void Nu_WriteFour(NuArchive* pArchive, FILE* fp, uint32_t val)
{
uint16_t dummyCrc CLEAN_INIT;
Nu_WriteFourC(pArchive, fp, val, &dummyCrc);
}
/*
* Read an 8-byte NuFX Date/Time structure.
*
* I've chosen *not* to filter away the Y2K differences between P8 ShrinkIt
* and GS/ShrinkIt. It's easy enough to deal with, and I figure the less
* messing-with, the better.
*/
NuDateTime Nu_ReadDateTimeC(NuArchive* pArchive, FILE* fp, uint16_t* pCrc)
{
NuDateTime temp;
int ic;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.second = ic;
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.minute = ic;
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.hour = ic;
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.year = ic;
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.day = ic;
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.month = ic;
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.extra = ic;
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
temp.weekDay = ic;
return temp;
}
NuDateTime Nu_ReadDateTime(NuArchive* pArchive, FILE* fp, uint16_t* pCrc)
{
uint16_t dummyCrc CLEAN_INIT;
return Nu_ReadDateTimeC(pArchive, fp, &dummyCrc);
}
/*
* Write an 8-byte NuFX Date/Time structure.
*/
void Nu_WriteDateTimeC(NuArchive* pArchive, FILE* fp, NuDateTime dateTime,
uint16_t* pCrc)
{
int ic;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
ic = dateTime.second;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
ic = dateTime.minute;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
ic = dateTime.hour;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
ic = dateTime.year;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
ic = dateTime.day;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
ic = dateTime.month;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
ic = dateTime.extra;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
ic = dateTime.weekDay;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
}
void Nu_WriteDateTime(NuArchive* pArchive, FILE* fp, NuDateTime dateTime)
{
uint16_t dummyCrc CLEAN_INIT;
Nu_WriteDateTimeC(pArchive, fp, dateTime, &dummyCrc);
}
/*
* Read N bytes from the stream, optionally computing a CRC.
*/
void Nu_ReadBytesC(NuArchive* pArchive, FILE* fp, void* vbuffer, long count,
uint16_t* pCrc)
{
uint8_t* buffer = vbuffer;
int ic;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
Assert(buffer != NULL);
Assert(count > 0);
while (count--) {
ic = getc(fp);
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
*buffer++ = ic;
}
}
void Nu_ReadBytes(NuArchive* pArchive, FILE* fp, void* vbuffer, long count)
{
uint16_t dummyCrc CLEAN_INIT;
Nu_ReadBytesC(pArchive, fp, vbuffer, count, &dummyCrc);
}
/*
* Write N bytes to the stream, optionally computing a CRC.
*/
void Nu_WriteBytesC(NuArchive* pArchive, FILE* fp, const void* vbuffer,
long count, uint16_t* pCrc)
{
const uint8_t* buffer = vbuffer;
int ic;
Assert(pArchive != NULL);
Assert(fp != NULL);
Assert(pCrc != NULL);
Assert(buffer != NULL);
Assert(count > 0);
while (count--) {
ic = *buffer++;
*pCrc = Nu_UpdateCRC16((uint8_t)ic, *pCrc);
putc(ic, fp);
}
}
void Nu_WriteBytes(NuArchive* pArchive, FILE* fp, const void* vbuffer,
long count)
{
uint16_t dummyCrc CLEAN_INIT;
Nu_WriteBytesC(pArchive, fp, vbuffer, count, &dummyCrc);
}
/*
* ===========================================================================
* General
* ===========================================================================
*/
/*
* Determine whether the stream completed the last set of operations
* successfully.
*/
NuError Nu_HeaderIOFailed(NuArchive* pArchive, FILE* fp)
{
if (feof(fp) || ferror(fp))
return kNuErrFile;
else
return kNuErrNone;
}
/*
* Seek around in an archive file. If this is a streaming-mode archive,
* we only allow forward relative seeks, which are emulated with read calls.
*
* The values for "ptrname" are the same as for fseek().
*/
NuError Nu_SeekArchive(NuArchive* pArchive, FILE* fp, long offset, int ptrname)
{
if (Nu_IsStreaming(pArchive)) {
Assert(ptrname == SEEK_CUR);
Assert(offset >= 0);
/* OPT: might be faster to fread a chunk at a time */
while (offset--)
(void) getc(fp);
if (ferror(fp) || feof(fp))
return kNuErrFileSeek;
} else {
if (fseek(fp, offset, ptrname) < 0)
return kNuErrFileSeek;
}
return kNuErrNone;
}
/*
* Rewind an archive to the start of NuFX record data.
*
* Note that rewind(3S) resets the error indication, but this doesn't.
*/
NuError Nu_RewindArchive(NuArchive* pArchive)
{
Assert(pArchive != NULL);
Assert(!Nu_IsStreaming(pArchive));
if (Nu_SeekArchive(pArchive, pArchive->archiveFp,
pArchive->headerOffset + kNuMasterHeaderSize, SEEK_SET) != 0)
return kNuErrFileSeek;
pArchive->currentOffset = pArchive->headerOffset + kNuMasterHeaderSize;
return kNuErrNone;
}