mirror of
https://github.com/RaySollium99/picodrive.git
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eff55556cf
git-svn-id: file:///home/notaz/opt/svn/PicoDrive@227 be3aeb3a-fb24-0410-a615-afba39da0efa
130 lines
2.7 KiB
C
130 lines
2.7 KiB
C
// Buffering handling
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// (c) Copyright 2007, Grazvydas "notaz" Ignotas
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#include "../PicoInt.h"
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//#include <stdlib.h>
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int PicoCDBuffers = 0;
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static unsigned char *cd_buffer = NULL;
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static int prev_lba = 0x80000000;
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static int hits, reads;
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void PicoCDBufferInit(void)
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{
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void *tmp;
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prev_lba = 0x80000000;
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hits = reads = 0;
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if (PicoCDBuffers <= 1) {
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PicoCDBuffers = 0;
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return; /* buffering off */
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}
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/* try alloc'ing until we succeed */
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while (PicoCDBuffers > 0)
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{
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tmp = realloc(cd_buffer, PicoCDBuffers * 2048);
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if (tmp != NULL) break;
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PicoCDBuffers >>= 1;
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}
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if (PicoCDBuffers <= 0) return; /* buffering became off */
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cd_buffer = tmp;
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}
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void PicoCDBufferFree(void)
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{
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if (cd_buffer) {
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free(cd_buffer);
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cd_buffer = NULL;
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}
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if (reads)
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printf("CD buffer hits: %i/%i (%i%%)\n", hits, reads, hits * 100 / reads);
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}
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/* this is a try to fight slow SD access of GP2X */
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PICO_INTERNAL void PicoCDBufferRead(void *dest, int lba)
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{
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int is_bin, offs, read_len, moved = 0;
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reads++;
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is_bin = Pico_mcd->TOC.Tracks[0].ftype == TYPE_BIN;
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if (PicoCDBuffers <= 0)
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{
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/* no buffering */
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int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
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pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
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pm_read(dest, 2048, Pico_mcd->TOC.Tracks[0].F);
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return;
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}
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/* hit? */
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offs = lba - prev_lba;
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if (offs >= 0 && offs < PicoCDBuffers)
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{
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hits++;
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if (offs == 0) dprintf("CD buffer seek to old %i -> %i\n", prev_lba, lba);
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memcpy32(dest, (int *)(cd_buffer + offs*2048), 2048/4);
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return;
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}
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if (prev_lba + PicoCDBuffers != lba)
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{
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int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
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dprintf("CD buffer seek %i -> %i\n", prev_lba, lba);
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pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
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}
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dprintf("CD buffer miss %i -> %i\n", prev_lba, lba);
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if (lba < prev_lba && prev_lba - lba < PicoCDBuffers)
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{
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read_len = prev_lba - lba;
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dprintf("CD buffer move=%i, read_len=%i", PicoCDBuffers - read_len, read_len);
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memmove(cd_buffer + read_len*2048, cd_buffer, (PicoCDBuffers - read_len)*2048);
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moved = 1;
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}
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else
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{
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read_len = PicoCDBuffers;
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}
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if (PicoMessage != NULL && read_len >= 512)
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{
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PicoMessage("Buffering data...");
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}
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if (is_bin)
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{
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int i;
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for (i = 0; i < read_len; i++)
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{
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pm_read(cd_buffer + i*2048, 2048, Pico_mcd->TOC.Tracks[0].F);
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pm_seek(Pico_mcd->TOC.Tracks[0].F, 304, SEEK_CUR);
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}
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}
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else
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{
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pm_read(cd_buffer, read_len*2048, Pico_mcd->TOC.Tracks[0].F);
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}
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memcpy32(dest, (int *) cd_buffer, 2048/4);
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prev_lba = lba;
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if (moved)
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{
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/* file pointer must point to the same data in file, as would-be data after our buffer */
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int where_seek;
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lba += PicoCDBuffers;
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where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
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pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
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}
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}
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