fix operator spr change ARM code bugs
[picodrive.git] / pico / cd / buffering.c
... / ...
CommitLineData
1// Buffering handling
2// (c) Copyright 2007, Grazvydas "notaz" Ignotas
3
4#include "../pico_int.h"
5
6int PicoCDBuffers = 0;
7static unsigned char *cd_buffer = NULL;
8static int prev_lba = 0x80000000;
9
10static int hits, reads;
11
12
13void PicoCDBufferInit(void)
14{
15 void *tmp = NULL;
16
17 prev_lba = 0x80000000;
18 hits = reads = 0;
19
20 if (PicoCDBuffers <= 1) {
21 PicoCDBuffers = 0;
22 return; /* buffering off */
23 }
24
25 /* try alloc'ing until we succeed */
26 while (PicoCDBuffers > 0)
27 {
28 tmp = realloc(cd_buffer, PicoCDBuffers * 2048 + 304);
29 if (tmp != NULL) break;
30 PicoCDBuffers >>= 1;
31 }
32
33 if (PicoCDBuffers <= 0) return; /* buffering became off */
34
35 cd_buffer = tmp;
36}
37
38
39void PicoCDBufferFree(void)
40{
41 if (cd_buffer) {
42 free(cd_buffer);
43 cd_buffer = NULL;
44 }
45 if (reads)
46 elprintf(EL_STATUS, "CD buffer hits: %i/%i (%i%%)\n", hits, reads, hits * 100 / reads);
47}
48
49
50void PicoCDBufferFlush(void)
51{
52 prev_lba = 0x80000000;
53}
54
55
56/* this is was a try to fight slow SD access of GP2X */
57PICO_INTERNAL void PicoCDBufferRead(void *dest, int lba)
58{
59 int is_bin, offs, read_len, moved = 0;
60 reads++;
61
62 is_bin = Pico_mcd->TOC.Tracks[0].ftype == TYPE_BIN;
63
64 if (PicoCDBuffers <= 0)
65 {
66 /* no buffering */
67 int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
68 pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
69 pm_read(dest, 2048, Pico_mcd->TOC.Tracks[0].F);
70 return;
71 }
72
73 /* hit? */
74 offs = lba - prev_lba;
75 if (offs >= 0 && offs < PicoCDBuffers)
76 {
77 hits++;
78 if (offs == 0) dprintf("CD buffer seek to old %i -> %i\n", prev_lba, lba);
79 memcpy32(dest, (int *)(cd_buffer + offs*2048), 2048/4);
80 return;
81 }
82
83 if (prev_lba + PicoCDBuffers != lba)
84 {
85 int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
86 dprintf("CD buffer seek %i -> %i\n", prev_lba, lba);
87 pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
88 }
89
90 dprintf("CD buffer miss %i -> %i\n", prev_lba, lba);
91
92 if (lba < prev_lba && prev_lba - lba < PicoCDBuffers)
93 {
94 read_len = prev_lba - lba;
95 dprintf("CD buffer move=%i, read_len=%i", PicoCDBuffers - read_len, read_len);
96 memmove(cd_buffer + read_len*2048, cd_buffer, (PicoCDBuffers - read_len)*2048);
97 moved = 1;
98 }
99 else
100 {
101 read_len = PicoCDBuffers;
102 }
103
104 if (PicoMessage != NULL && read_len >= 512)
105 {
106 PicoMessage("Buffering data...");
107 }
108
109 if (is_bin)
110 {
111 int i = 0;
112#if REDUCE_IO_CALLS
113 int bufs = (read_len*2048) / (2048+304);
114 pm_read(cd_buffer, bufs*(2048+304), Pico_mcd->TOC.Tracks[0].F);
115 for (i = 1; i < bufs; i++)
116 // should really use memmove here, but my memcpy32 implementation is also suitable here
117 memcpy32((int *)(cd_buffer + i*2048), (int *)(cd_buffer + i*(2048+304)), 2048/4);
118#endif
119 for (; i < read_len - 1; i++)
120 {
121 pm_read(cd_buffer + i*2048, 2048 + 304, Pico_mcd->TOC.Tracks[0].F);
122 // pm_seek(Pico_mcd->TOC.Tracks[0].F, 304, SEEK_CUR); // seeking is slower, in PSP case even more
123 }
124 // further data might be moved, do not overwrite
125 pm_read(cd_buffer + i*2048, 2048, Pico_mcd->TOC.Tracks[0].F);
126 pm_seek(Pico_mcd->TOC.Tracks[0].F, 304, SEEK_CUR);
127 }
128 else
129 {
130 pm_read(cd_buffer, read_len*2048, Pico_mcd->TOC.Tracks[0].F);
131 }
132 memcpy32(dest, (int *) cd_buffer, 2048/4);
133 prev_lba = lba;
134
135 if (moved)
136 {
137 /* file pointer must point to the same data in file, as would-be data after our buffer */
138 int where_seek;
139 lba += PicoCDBuffers;
140 where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
141 pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
142 }
143}
144