summaryrefslogtreecommitdiff
path: root/lib/fprint.c
blob: 65f70590771a434e24272d0958bcddae8bb92a92 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
#include "system.h"

/**
 * \file lib/fprint.c
 */

#include <rpmlib.h>
#include <rpmmacro.h>	/* XXX for rpmCleanPath */

#include "fprint.h"

fingerPrintCache fpCacheCreate(int sizeHint)
{
    fingerPrintCache fpc;

    fpc = xmalloc(sizeof(*fpc));
    fpc->ht = htCreate(sizeHint * 2, 0, 1, hashFunctionString,
		       hashEqualityString);
    return fpc;
}

void fpCacheFree(fingerPrintCache cache)
{
    htFree(cache->ht);
    free(cache);
}

/**
 * Find directory name entry in cache.
 * @param cache		pointer to fingerprint cache
 * @param dirName	string to locate in cache
 * @return pointer to directory name entry (or NULL if not found).
 */
static const struct fprintCacheEntry_s * cacheContainsDirectory(
			    fingerPrintCache cache,
			    const char * dirName)
{
    const void ** data;

    if (htGetEntry(cache->ht, dirName, &data, NULL, NULL))
	return NULL;
    return data[0];
}

/**
 * Return finger print of a file path.
 * @param cache		pointer to fingerprint cache
 * @param dirName	leading directory name of path
 * @param baseName	file name of path
 * @param scareMemory
 * @return pointer to the finger print associated with a file path.
 */
static fingerPrint doLookup(fingerPrintCache cache,
	const char * dirName, const char * baseName, int scareMemory)
{
    char dir[PATH_MAX];
    const char * cleanDirName;
    size_t cdnl;
    char * end;		    /* points to the '\0' at the end of "buf" */
    fingerPrint fp;
    struct stat sb;
    char * buf;
    const struct fprintCacheEntry_s * cacheHit;

    /* assert(*dirName == '/' || !scareMemory); */

    /* XXX WATCHOUT: fp.subDir is set below from relocated dirName arg */
    cleanDirName = dirName;
    cdnl = strlen(cleanDirName);

    if (*cleanDirName == '/') {
	if (!scareMemory)
	    cleanDirName =
		rpmCleanPath(strcpy(alloca(cdnl+1), dirName));
    } else {
	scareMemory = 0;	/* XXX causes memory leak */

	/* Using realpath on the arg isn't correct if the arg is a symlink,
	 * especially if the symlink is a dangling link.  What we 
	 * do instead is use realpath() on `.' and then append arg to
	 * the result.
	 */

	/* if the current directory doesn't exist, we might fail. 
	   oh well. likewise if it's too long.  */
	dir[0] = '\0';
	if ( /*@-unrecog@*/ realpath(".", dir) /*@=unrecog@*/ != NULL) {
	    end = dir + strlen(dir);
	    if (end[-1] != '/')	*end++ = '/';
	    end = stpncpy(end, cleanDirName, sizeof(dir) - (end - dir));
	    *end = '\0';
	    (void)rpmCleanPath(dir); /* XXX possible /../ from concatenation */
	    end = dir + strlen(dir);
	    if (end[-1] != '/')	*end++ = '/';
	    *end = '\0';
	    cleanDirName = dir;
	    cdnl = end - dir;
	}
    }

    buf = strcpy(alloca(cdnl + 1), cleanDirName);
    end = buf + cdnl;

    /* no need to pay attention to that extra little / at the end of dirName */
    if (buf[1] && end[-1] == '/') {
	end--;
	*end = '\0';
    }

    fp.entry = NULL;
    fp.subDir = NULL;
    fp.baseName = NULL;
    while (1) {

	/* as we're stating paths here, we want to follow symlinks */

	if ((cacheHit = cacheContainsDirectory(cache, *buf ? buf : "/"))) {
	    fp.entry = cacheHit;
	} else if (!stat(*buf ? buf : "/", &sb)) {
	    size_t nb = sizeof(*fp.entry) + (*buf ? (end-buf) : 1) + 1;
	    char * dn = xmalloc(nb);
	    struct fprintCacheEntry_s * newEntry = (void *)dn;

	    dn += sizeof(*newEntry);
	    strcpy(dn, (*buf ? buf : "/"));
	    newEntry->ino = sb.st_ino;
	    newEntry->dev = sb.st_dev;
	    newEntry->isFake = 0;
	    newEntry->dirName = dn;
	    fp.entry = newEntry;

	    htAddEntry(cache->ht, dn, fp.entry);
	}

        if (fp.entry) {
	    fp.subDir = cleanDirName + (end - buf);
	    if (fp.subDir[0] == '/' && fp.subDir[1] != '\0')
		fp.subDir++;
	    if (fp.subDir[0] == '\0' ||
	    /* XXX don't bother saving '/' as subdir */
	       (fp.subDir[0] == '/' && fp.subDir[1] == '\0'))
		fp.subDir = NULL;
	    fp.baseName = baseName;
	    if (!scareMemory && fp.subDir != NULL)
		fp.subDir = xstrdup(fp.subDir);
	    return fp;
	}

        /* stat of '/' just failed! */
	if (end == buf + 1)
	    abort();

	end--;
	while ((end > buf) && *end != '/') end--;
	if (end == buf)	    /* back to stat'ing just '/' */
	    end++;

	*end = '\0';
    }

    /*@notreached@*/

    return fp;
}

fingerPrint fpLookup(fingerPrintCache cache, const char * dirName, 
			const char * baseName, int scareMemory)
{
    return doLookup(cache, dirName, baseName, scareMemory);
}

unsigned int fpHashFunction(const void * key)
{
    const fingerPrint * fp = key;
    unsigned int hash = 0;
    char ch;
    const char * chptr;

    ch = 0;
    chptr = fp->baseName;
    while (*chptr) ch ^= *chptr++;

    hash |= ((unsigned)ch) << 24;
    hash |= (((((unsigned)fp->entry->dev) >> 8) ^ fp->entry->dev) & 0xFF) << 16;
    hash |= fp->entry->ino & 0xFFFF;
    
    return hash;
}

int fpEqual(const void * key1, const void * key2)
{
    const fingerPrint *k1 = key1;
    const fingerPrint *k2 = key2;

    /* If the addresses are the same, so are the values. */
    if (k1 == k2)
	return 0;

    /* Otherwise, compare fingerprints by value. */
    if (FP_EQUAL(*k1, *k2))
	return 0;
    return 1;

}

void fpLookupList(fingerPrintCache cache, const char ** dirNames, 
		  const char ** baseNames, const int * dirIndexes, 
		  int fileCount, fingerPrint * fpList)
{
    int i;

    for (i = 0; i < fileCount; i++) {
	/* If this is in the same directory as the last file, don't bother
	   redoing all of this work */
	if (i > 0 && dirIndexes[i - 1] == dirIndexes[i]) {
	    fpList[i].entry = fpList[i - 1].entry;
	    fpList[i].subDir = fpList[i - 1].subDir;
	    fpList[i].baseName = baseNames[i];
	} else {
	    fpList[i] = doLookup(cache, dirNames[dirIndexes[i]], baseNames[i],
				 1);
	}
    }
}

void fpLookupHeader(fingerPrintCache cache, Header h, fingerPrint * fpList)
{
    int fileCount;
    const char ** baseNames, ** dirNames;
    int_32 * dirIndexes;

    if (!headerGetEntryMinMemory(h, RPMTAG_BASENAMES, NULL, 
			(void **) &baseNames, &fileCount)) return;
    headerGetEntryMinMemory(h, RPMTAG_DIRNAMES, NULL, (void **) &dirNames, 
			NULL);
    headerGetEntry(h, RPMTAG_DIRINDEXES, NULL, (void **) &dirIndexes, NULL);
			
    fpLookupList(cache, dirNames, baseNames, dirIndexes, fileCount, fpList);

    free(dirNames);
    free(baseNames);
}