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f5bcab4b WJ |
1 | /* recycle.c */ |
2 | ||
3 | /* Author: | |
4 | * Steve Kirkendall | |
5 | * 14407 SW Teal Blvd. #C | |
6 | * Beaverton, OR 97005 | |
7 | * kirkenda@cs.pdx.edu | |
8 | */ | |
9 | ||
10 | ||
11 | /* This file contains the functions perform garbage collection and allocate | |
12 | * reusable blocks. | |
13 | */ | |
14 | ||
15 | #include "config.h" | |
16 | #include "vi.h" | |
17 | ||
18 | #ifndef NO_RECYCLE | |
19 | /* this whole file would have be skipped if NO_RECYCLE is defined */ | |
20 | ||
21 | ||
22 | #define BTST(bitno, byte) ((byte) & (1 << (bitno))) | |
23 | #define BSET(bitno, byte) ((byte) |= (1 << (bitno))) | |
24 | #define BCLR(bitno, byte) ((byte) &= ~(1 << (bitno))) | |
25 | ||
26 | #define TST(blkno) ((blkno) < MAXBIT ? BTST((blkno) & 7, bitmap[(blkno) >> 3]) : 1) | |
27 | #define SET(blkno) if ((blkno) < MAXBIT) BSET((blkno) & 7, bitmap[(blkno) >> 3]) | |
28 | #define CLR(blkno) if ((blkno) < MAXBIT) BCLR((blkno) & 7, bitmap[(blkno) >> 3]) | |
29 | ||
30 | /* bitmap of free blocks in first 4096k of tmp file */ | |
31 | static unsigned char bitmap[512]; | |
32 | #define MAXBIT (sizeof bitmap << 3) | |
33 | ||
34 | /* this function locates all free blocks in the current tmp file */ | |
35 | void garbage() | |
36 | { | |
37 | int i; | |
38 | BLK oldhdr; | |
39 | ||
40 | /* start by assuming every block is free */ | |
41 | for (i = 0; i < sizeof bitmap; i++) | |
42 | { | |
43 | bitmap[i] = 255; | |
44 | } | |
45 | ||
46 | /* header blocks aren't free */ | |
47 | #ifndef lint | |
48 | CLR(0); | |
49 | CLR(1); | |
50 | #endif | |
51 | ||
52 | /* blocks needed for current hdr aren't free */ | |
53 | for (i = 1; i < MAXBLKS; i++) | |
54 | { | |
55 | CLR(hdr.n[i]); | |
56 | } | |
57 | ||
58 | /* blocks needed for undo version aren't free */ | |
59 | lseek(tmpfd, 0L, 0); | |
60 | if (read(tmpfd, &oldhdr, (unsigned)sizeof oldhdr) != sizeof oldhdr) | |
61 | { | |
62 | msg("garbage() failed to read oldhdr??"); | |
63 | for (i = 0; i < sizeof bitmap; i++) | |
64 | { | |
65 | bitmap[i] = 0; | |
66 | } | |
67 | return; | |
68 | } | |
69 | for (i = 1; i < MAXBLKS; i++) | |
70 | { | |
71 | CLR(oldhdr.n[i]); | |
72 | } | |
73 | ||
74 | /* blocks needed for cut buffers aren't free */ | |
75 | for (i = cutneeds(&oldhdr) - 1; i >= 0; i--) | |
76 | { | |
77 | CLR(oldhdr.n[i]); | |
78 | } | |
79 | } | |
80 | ||
81 | /* This function allocates the first available block in the tmp file */ | |
82 | long allocate() | |
83 | { | |
84 | int i; | |
85 | long offset; | |
86 | ||
87 | /* search for the first byte with a free bit set */ | |
88 | for (i = 0; i < sizeof bitmap && bitmap[i] == 0; i++) | |
89 | { | |
90 | } | |
91 | ||
92 | /* if we hit the end of the bitmap, return the end of the file */ | |
93 | if (i == sizeof bitmap) | |
94 | { | |
95 | offset = lseek(tmpfd, 0L, 2); | |
96 | } | |
97 | else /* compute the offset for the free block */ | |
98 | { | |
99 | for (i <<= 3; TST(i) == 0; i++) | |
100 | { | |
101 | } | |
102 | offset = (long)i * (long)BLKSIZE; | |
103 | ||
104 | /* mark the block as "allocated" */ | |
105 | CLR(i); | |
106 | } | |
107 | ||
108 | return offset; | |
109 | } | |
110 | ||
111 | #endif | |
112 | ||
113 | #ifdef DEBUG | |
114 | # include <stdio.h> | |
115 | # undef malloc | |
116 | # undef free | |
117 | # define MEMMAGIC 0x19f72cc0L | |
118 | # define MAXALLOC 800 | |
119 | static char *allocated[MAXALLOC]; | |
120 | static char *fromfile[MAXALLOC]; | |
121 | static int fromline[MAXALLOC]; | |
122 | static int sizes[MAXALLOC]; | |
123 | ||
124 | char *dbmalloc(size, file, line) | |
125 | int size; | |
126 | char *file; | |
127 | int line; | |
128 | { | |
129 | char *ret; | |
130 | int i; | |
131 | ||
132 | size = size + sizeof(long) - (size % sizeof(long)); | |
133 | ret = (char *)malloc(size + 2 * sizeof(long)) + sizeof(long); | |
134 | for (i = 0; i < MAXALLOC && allocated[i]; i++) | |
135 | { | |
136 | } | |
137 | if (i == MAXALLOC) | |
138 | { | |
139 | endwin(); | |
140 | fprintf(stderr, "\r\n%s(%d): Too many malloc calls!\n", file, line); | |
141 | abort(); | |
142 | } | |
143 | sizes[i] = size/sizeof(long); | |
144 | allocated[i] = ret; | |
145 | fromfile[i] = file; | |
146 | fromline[i] = line; | |
147 | ((long *)ret)[-1] = MEMMAGIC; | |
148 | ((long *)ret)[sizes[i]] = MEMMAGIC; | |
149 | return ret; | |
150 | } | |
151 | ||
152 | dbfree(ptr, file, line) | |
153 | char *ptr; | |
154 | char *file; | |
155 | int line; | |
156 | { | |
157 | int i; | |
158 | ||
159 | for (i = 0; i < MAXALLOC && allocated[i] != ptr; i++) | |
160 | { | |
161 | } | |
162 | if (i == MAXALLOC) | |
163 | { | |
164 | endwin(); | |
165 | fprintf(stderr, "\r\n%s(%d): attempt to free mem that wasn't allocated\n", file, line); | |
166 | abort(); | |
167 | } | |
168 | allocated[i] = (char *)0; | |
169 | if (((long *)ptr)[-1] != MEMMAGIC) | |
170 | { | |
171 | endwin(); | |
172 | fprintf(stderr, "\r\n%s(%d): underflowed malloc space, allocated at %s(%d)\n", file, line, fromfile[i], fromline[i]); | |
173 | abort(); | |
174 | } | |
175 | if (((long *)ptr)[sizes[i]] != MEMMAGIC) | |
176 | { | |
177 | endwin(); | |
178 | fprintf(stderr, "\r\n%s(%d): overflowed malloc space, allocated at %s(%d)\n", file, line, fromfile[i], fromline[i]); | |
179 | abort(); | |
180 | } | |
181 | free(ptr - sizeof(long)); | |
182 | } | |
183 | #endif |