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1 | // Buffering handling |
2 | // (c) Copyright 2007, Grazvydas "notaz" Ignotas |
3 | |
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4 | #include "../PicoInt.h" |
5 | |
6 | //#include <stdlib.h> |
7 | |
8 | int PicoCDBuffers = 0; |
9 | static unsigned char *cd_buffer = NULL; |
10 | static int prev_lba = 0x80000000; |
11 | |
12 | static int hits, reads; |
13 | |
14 | |
15 | void 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 | |
41 | void 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 */ |
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53 | PICO_INTERNAL void PicoCDBufferRead(void *dest, int lba) |
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54 | { |
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55 | int is_bin, offs, read_len, moved = 0; |
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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 | { |
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90 | read_len = prev_lba - lba; |
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91 | dprintf("CD buffer move=%i, read_len=%i", PicoCDBuffers - read_len, read_len); |
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92 | memmove(cd_buffer + read_len*2048, cd_buffer, (PicoCDBuffers - read_len)*2048); |
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93 | moved = 1; |
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94 | } |
95 | else |
96 | { |
97 | read_len = PicoCDBuffers; |
98 | } |
99 | |
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100 | if (PicoMessage != NULL && read_len >= 512) |
101 | { |
102 | PicoMessage("Buffering data..."); |
103 | } |
104 | |
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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; |
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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 | } |
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129 | } |
130 | |