![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to find.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [CSRG BSD Unix] / 42BSD / ingres / source / iutil|
Return to find.c CVS log | Up to [CSRG BSD Unix] / 42BSD / ingres / source / iutil |
1.1 root 1: # include <ingres.h>
2: # include <aux.h>
3: # include <symbol.h>
4: # include <access.h>
5: # include <lock.h>
6: # include <sccs.h>
7:
8: SCCSID(@(#)find.c 7.1 2/5/81)
9:
10:
11: /*
12: ** Find - determine limits for scan of a relation
13: **
14: ** Find determines the values of an initial TID
15: ** and an ending TID for scanning a relation.
16: ** The possible calls to find are:
17: **
18: ** find(desc, NOKEY, lotid, hightid)
19: ** sets tids to scan entire relation
20: **
21: ** find(desc, EXACTKEY, lotid, hightid, key)
22: ** sets tids according to structure
23: ** of the relation. Key should have
24: ** been build using setkey.
25: **
26: ** find(desc, LRANGEKEY, lotid, hightid, keylow)
27: ** Finds lotid less then or equal to keylow
28: ** for isam relations. Otherwise scans whole relation.
29: ** This call should be followed by a call with HRANGEKEY.
30: **
31: ** find(desc, HRANGEKEY, lotid, hightid, keyhigh)
32: ** Finds hightid greater than or equal to
33: ** keyhigh for isam relations. Otherwise sets
34: ** hightid to maximum scan.
35: **
36: ** find(desc, FULLKEY, lotid, hightid, key)
37: ** Same as find with EXACTKEY and all keys
38: ** provided. This mode is used only by findbest
39: ** and replace.
40: **
41: ** returns:
42: ** <0 fatal error
43: ** 0 success
44: **
45: ** Trace Flags:
46: ** 22.0-8
47: */
48:
49:
50: find(d, mode, lotid, hightid, key)
51: register DESC *d;
52: int mode;
53: TID *lotid;
54: TID *hightid;
55: char *key;
56: {
57: register int ret;
58: bool keyok;
59: long pageid;
60: long rhash();
61:
62: # ifdef xATR1
63: if (tTf(22, 0))
64: {
65: printf("find: m%d,s%d,%.14s\n", mode, d->reldum.relspec, d->reldum.relid);
66: if (mode != NOKEY)
67: printup(d, key);
68: }
69: # endif
70:
71: ret = 0; /* assume successful return */
72: keyok = FALSE;
73:
74: switch (mode)
75: {
76:
77: case EXACTKEY:
78: keyok = fullkey(d);
79: break;
80:
81: case FULLKEY:
82: keyok = TRUE;
83:
84: case NOKEY:
85: case LRANGEKEY:
86: case HRANGEKEY:
87: break;
88:
89: default:
90: syserr("FIND: bad mode %d", mode);
91: }
92:
93: /* set lotid for beginning of scan */
94: if (mode != HRANGEKEY)
95: {
96: pageid = 0;
97: stuff_page(lotid, &pageid);
98: lotid->line_id = -1;
99: }
100:
101: /* set hitid for end of scan */
102: if (mode != LRANGEKEY)
103: {
104: pageid = -1;
105: stuff_page(hightid, &pageid);
106: hightid->line_id = -1;
107: }
108:
109: if (mode != NOKEY)
110: {
111: switch (abs(d->reldum.relspec))
112: {
113:
114: case M_HEAP:
115: break;
116:
117: case M_ISAM:
118: if (mode != HRANGEKEY)
119: {
120: /* compute lo limit */
121: if (ret = ndxsearch(d, lotid, key, -1, keyok))
122: break; /* fatal error */
123: }
124:
125: /* if the full key was provided and mode is exact, then done */
126: if (keyok)
127: {
128: bmove((char *) lotid, (char *) hightid, sizeof *lotid);
129: break;
130: }
131:
132: if (mode != LRANGEKEY)
133: ret = ndxsearch(d, hightid, key, 1, keyok);
134: break;
135:
136: case M_HASH:
137: if (!keyok)
138: break; /* can't do anything */
139: pageid = rhash(d, key);
140: stuff_page(lotid, &pageid);
141: stuff_page(hightid, &pageid);
142: break;
143:
144: default:
145: ret = acc_err(AMFIND_ERR);
146: }
147: }
148:
149: # ifdef xATR2
150: if (tTf(22, 1))
151: {
152: printf("find: ret %d\tlow", ret);
153: dumptid(lotid);
154: printf("hi");
155: dumptid(hightid);
156: }
157: # endif
158: return (ret);
159: }
160: /*
161: ** This routine will check that enough of the tuple has been specified
162: ** to enable a key access.
163: */
164:
165: fullkey(des)
166: DESC *des;
167: {
168: register DESC *d;
169: register int i;
170:
171: d = des;
172: for (i = 1; i <= d->reldum.relatts; i++)
173: if (d->relxtra[i] && !d->relgiven[i])
174: return (FALSE);
175: return (TRUE);
176: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.