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- // Buffering handling
- // (c) Copyright 2007, Grazvydas "notaz" Ignotas
- #include "../PicoInt.h"
- int PicoCDBuffers = 0;
- static unsigned char *cd_buffer = NULL;
- static int prev_lba = 0x80000000;
- static int hits, reads;
- void PicoCDBufferInit(void)
- {
- void *tmp = NULL;
- prev_lba = 0x80000000;
- hits = reads = 0;
- if (PicoCDBuffers <= 1) {
- PicoCDBuffers = 0;
- return; /* buffering off */
- }
- /* try alloc'ing until we succeed */
- while (PicoCDBuffers > 0)
- {
- tmp = realloc(cd_buffer, PicoCDBuffers * 2048 + 304);
- if (tmp != NULL) break;
- PicoCDBuffers >>= 1;
- }
- if (PicoCDBuffers <= 0) return; /* buffering became off */
- cd_buffer = tmp;
- }
- void PicoCDBufferFree(void)
- {
- if (cd_buffer) {
- free(cd_buffer);
- cd_buffer = NULL;
- }
- if (reads)
- elprintf(EL_STATUS, "CD buffer hits: %i/%i (%i%%)\n", hits, reads, hits * 100 / reads);
- }
- void PicoCDBufferFlush(void)
- {
- prev_lba = 0x80000000;
- }
- /* this is was a try to fight slow SD access of GP2X */
- PICO_INTERNAL void PicoCDBufferRead(void *dest, int lba)
- {
- int is_bin, offs, read_len, moved = 0;
- reads++;
- is_bin = Pico_mcd->TOC.Tracks[0].ftype == TYPE_BIN;
- if (PicoCDBuffers <= 0)
- {
- /* no buffering */
- int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
- pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
- pm_read(dest, 2048, Pico_mcd->TOC.Tracks[0].F);
- return;
- }
- /* hit? */
- offs = lba - prev_lba;
- if (offs >= 0 && offs < PicoCDBuffers)
- {
- hits++;
- if (offs == 0) dprintf("CD buffer seek to old %i -> %i\n", prev_lba, lba);
- memcpy32(dest, (int *)(cd_buffer + offs*2048), 2048/4);
- return;
- }
- if (prev_lba + PicoCDBuffers != lba)
- {
- int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
- dprintf("CD buffer seek %i -> %i\n", prev_lba, lba);
- pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
- }
- dprintf("CD buffer miss %i -> %i\n", prev_lba, lba);
- if (lba < prev_lba && prev_lba - lba < PicoCDBuffers)
- {
- read_len = prev_lba - lba;
- dprintf("CD buffer move=%i, read_len=%i", PicoCDBuffers - read_len, read_len);
- memmove(cd_buffer + read_len*2048, cd_buffer, (PicoCDBuffers - read_len)*2048);
- moved = 1;
- }
- else
- {
- read_len = PicoCDBuffers;
- }
- if (PicoMessage != NULL && read_len >= 512)
- {
- PicoMessage("Buffering data...");
- }
- if (is_bin)
- {
- int i = 0;
- #if REDUCE_IO_CALLS
- int bufs = (read_len*2048) / (2048+304);
- pm_read(cd_buffer, bufs*(2048+304), Pico_mcd->TOC.Tracks[0].F);
- for (i = 1; i < bufs; i++)
- // should really use memmove here, but my memcpy32 implementation is also suitable here
- memcpy32((int *)(cd_buffer + i*2048), (int *)(cd_buffer + i*(2048+304)), 2048/4);
- #endif
- for (; i < read_len - 1; i++)
- {
- pm_read(cd_buffer + i*2048, 2048 + 304, Pico_mcd->TOC.Tracks[0].F);
- // pm_seek(Pico_mcd->TOC.Tracks[0].F, 304, SEEK_CUR); // seeking is slower, in PSP case even more
- }
- // further data might be moved, do not overwrite
- pm_read(cd_buffer + i*2048, 2048, Pico_mcd->TOC.Tracks[0].F);
- pm_seek(Pico_mcd->TOC.Tracks[0].F, 304, SEEK_CUR);
- }
- else
- {
- pm_read(cd_buffer, read_len*2048, Pico_mcd->TOC.Tracks[0].F);
- }
- memcpy32(dest, (int *) cd_buffer, 2048/4);
- prev_lba = lba;
- if (moved)
- {
- /* file pointer must point to the same data in file, as would-be data after our buffer */
- int where_seek;
- lba += PicoCDBuffers;
- where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
- pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
- }
- }
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