giz rc1 release
[picodrive.git] / Pico / cd / buffering.c
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CommitLineData
1// Buffering handling
2// (c) Copyright 2007, Grazvydas "notaz" Ignotas
3
4#include "../PicoInt.h"
5
6//#include <stdlib.h>
7
8int PicoCDBuffers = 0;
9static unsigned char *cd_buffer = NULL;
10static int prev_lba = 0x80000000;
11
12static int hits, reads;
13
14
15void PicoCDBufferInit(void)
16{
17 void *tmp;
18
19 prev_lba = 0x80000000;
20 hits = reads = 0;
21
22 if (PicoCDBuffers <= 1) {
23 PicoCDBuffers = 0;
24 return; /* buffering off */
25 }
26
27 /* try alloc'ing until we succeed */
28 while (PicoCDBuffers > 0)
29 {
30 tmp = realloc(cd_buffer, PicoCDBuffers * 2048);
31 if (tmp != NULL) break;
32 PicoCDBuffers >>= 1;
33 }
34
35 if (PicoCDBuffers <= 0) return; /* buffering became off */
36
37 cd_buffer = tmp;
38}
39
40
41void PicoCDBufferFree(void)
42{
43 if (cd_buffer) {
44 free(cd_buffer);
45 cd_buffer = NULL;
46 }
47 if (reads)
48 printf("CD buffer hits: %i/%i (%i%%)\n", hits, reads, hits * 100 / reads);
49}
50
51
52/* this is a try to fight slow SD access of GP2X */
53PICO_INTERNAL void PicoCDBufferRead(void *dest, int lba)
54{
55 int is_bin, offs, read_len, moved = 0;
56 reads++;
57
58 is_bin = Pico_mcd->TOC.Tracks[0].ftype == TYPE_BIN;
59
60 if (PicoCDBuffers <= 0)
61 {
62 /* no buffering */
63 int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
64 pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
65 pm_read(dest, 2048, Pico_mcd->TOC.Tracks[0].F);
66 return;
67 }
68
69 /* hit? */
70 offs = lba - prev_lba;
71 if (offs >= 0 && offs < PicoCDBuffers)
72 {
73 hits++;
74 if (offs == 0) dprintf("CD buffer seek to old %i -> %i\n", prev_lba, lba);
75 memcpy32(dest, (int *)(cd_buffer + offs*2048), 2048/4);
76 return;
77 }
78
79 if (prev_lba + PicoCDBuffers != lba)
80 {
81 int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
82 dprintf("CD buffer seek %i -> %i\n", prev_lba, lba);
83 pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
84 }
85
86 dprintf("CD buffer miss %i -> %i\n", prev_lba, lba);
87
88 if (lba < prev_lba && prev_lba - lba < PicoCDBuffers)
89 {
90 read_len = prev_lba - lba;
91 dprintf("CD buffer move=%i, read_len=%i", PicoCDBuffers - read_len, read_len);
92 memmove(cd_buffer + read_len*2048, cd_buffer, (PicoCDBuffers - read_len)*2048);
93 moved = 1;
94 }
95 else
96 {
97 read_len = PicoCDBuffers;
98 }
99
100 if (PicoMessage != NULL && read_len >= 512)
101 {
102 PicoMessage("Buffering data...");
103 }
104
105 if (is_bin)
106 {
107 int i;
108 for (i = 0; i < read_len; i++)
109 {
110 pm_read(cd_buffer + i*2048, 2048, Pico_mcd->TOC.Tracks[0].F);
111 pm_seek(Pico_mcd->TOC.Tracks[0].F, 304, SEEK_CUR);
112 }
113 }
114 else
115 {
116 pm_read(cd_buffer, read_len*2048, Pico_mcd->TOC.Tracks[0].F);
117 }
118 memcpy32(dest, (int *) cd_buffer, 2048/4);
119 prev_lba = lba;
120
121 if (moved)
122 {
123 /* file pointer must point to the same data in file, as would-be data after our buffer */
124 int where_seek;
125 lba += PicoCDBuffers;
126 where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
127 pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
128 }
129}
130