lowercasing filenames, part3

[picodrive.git] / pico / cd / buffering.c

diff --git a/pico/cd/buffering.c b/pico/cd/buffering.c
new file mode 100644 (file)
index 0000000..dbf7b28
--- /dev/null
+++ b/pico/cd/buffering.c
@@ -0,0 +1,144 @@
+// Buffering handling
+// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+
+#include "../pico_int.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);
+       }
+}
+