Actual source code: ctable.c

  1: #define PETSC_DLL
  2: /* Contributed by - Mark Adams */

 4:  #include petsc.h
 5:  #include src/sys/ctable.h
  6: #if defined (PETSC_HAVE_LIMITS_H)
  7: #include <limits.h>
  8: #endif
  9: #define HASH_FACT 79943
 10: #define HASHT(ta,x) ((unsigned long)((HASH_FACT*(unsigned long)x)%ta->tablesize))

 14: /* PetscTableCreate() ********************************************
 15:  * 
 16:  * hash table for non-zero data and keys 
 17:  *
 18:  */
 19: PetscErrorCode  PetscTableCreate(const PetscInt n,PetscTable *rta)
 20: {
 21:   PetscTable     ta;

 25:   if (n < 0) SETERRQ(PETSC_ERR_ARG_OUTOFRANGE,"n < 0");
 26:   PetscNew(struct _n_PetscTable,&ta);
 27:   ta->tablesize = (3*n)/2 + 17;
 28:   if (ta->tablesize < n) ta->tablesize = INT_MAX/4; /* overflow */
 29:   PetscMalloc(sizeof(PetscInt)*ta->tablesize,&ta->keytable);
 30:   PetscMemzero(ta->keytable,sizeof(PetscInt)*ta->tablesize);
 31:   PetscMalloc(sizeof(PetscInt)*ta->tablesize,&ta->table);
 32:   ta->head      = 0;
 33:   ta->count     = 0;
 34:   *rta          = ta;
 35:   return(0);
 36: }

 40: /* PetscTableCreate() ********************************************
 41:  * 
 42:  * hash table for non-zero data and keys 
 43:  *
 44:  */
 45: PetscErrorCode  PetscTableCreateCopy(const PetscTable intable,PetscTable *rta)
 46: {
 48:   PetscInt       i;
 49:   PetscTable     ta;

 52:   PetscNew(struct _n_PetscTable,&ta);
 53:   ta->tablesize = intable->tablesize;
 54:   PetscMalloc(sizeof(PetscInt)*ta->tablesize,&ta->keytable);
 55:   PetscMalloc(sizeof(PetscInt)*ta->tablesize,&ta->table);
 56:   for(i = 0 ; i < ta->tablesize ; i++){
 57:     ta->keytable[i] = intable->keytable[i];
 58:     ta->table[i]    = intable->table[i];
 59: #if defined(PETSC_USE_DEBUG)    
 60:     if (ta->keytable[i] < 0) SETERRQ(PETSC_ERR_COR,"ta->keytable[i] < 0");
 61: #endif  
 62:  }
 63:   ta->head  = 0;
 64:   ta->count = intable->count;
 65:   *rta      = ta;
 66:   return(0);
 67: }

 71: /* PetscTableDelete() ********************************************
 72:  * 
 73:  *
 74:  */
 75: PetscErrorCode  PetscTableDelete(PetscTable ta)
 76: {

 80:   PetscFree(ta->keytable);
 81:   PetscFree(ta->table);
 82:   PetscFree(ta);
 83:   return(0);
 84: }
 87: /* PetscTableGetCount() ********************************************
 88:  */
 89: PetscErrorCode  PetscTableGetCount(const PetscTable ta,PetscInt *count)
 90: {
 92:   *count = ta->count;
 93:   return(0);
 94: }

 98: /* PetscTableIsEmpty() ********************************************
 99:  */
100: PetscErrorCode  PetscTableIsEmpty(const PetscTable ta,PetscInt *flag)
101: {
103:   *flag = !(ta->count);
104:   return(0);
105: }

109: /* PetscTableAdd() ********************************************
110:  *
111:  */
112: PetscErrorCode  PetscTableAdd(PetscTable ta,const PetscInt key,const PetscInt data)
113: {
115:   PetscInt       ii = 0,hash = HASHT(ta,key);
116:   const PetscInt tsize = ta->tablesize,tcount = ta->count;
117: 
119:   if (key <= 0) SETERRQ(PETSC_ERR_COR,"key <= 0");
120:   if (!data) SETERRQ(PETSC_ERR_COR,"Null data");
121: 
122:   if (ta->count < 5*(ta->tablesize/6) - 1) {
123:     while (ii++ < ta->tablesize){
124:       if (ta->keytable[hash] == key) {
125:         ta->table[hash] = data; /* over write */
126:         return(0);
127:       } else if (!ta->keytable[hash]) {
128:         ta->count++; /* add */
129:         ta->keytable[hash] = key; ta->table[hash] = data;
130:         return(0);
131:       }
132:       hash = (hash == (ta->tablesize-1)) ? 0 : hash+1;
133:     }
134:     SETERRQ(PETSC_ERR_COR,"Full table");
135:   } else {
136:     PetscInt *oldtab = ta->table,*oldkt = ta->keytable,newk,ndata;

138:     /* alloc new (bigger) table */
139:     if (ta->tablesize == INT_MAX/4) SETERRQ(PETSC_ERR_COR,"ta->tablesize < 0");
140:     ta->tablesize = 2*tsize;
141:     if (ta->tablesize <= tsize) ta->tablesize = INT_MAX/4;

143:     PetscMalloc(ta->tablesize*sizeof(PetscInt),&ta->table);
144:     PetscMalloc(ta->tablesize*sizeof(PetscInt),&ta->keytable);
145:     PetscMemzero(ta->keytable,ta->tablesize*sizeof(PetscInt));

147:     ta->count     = 0;
148:     ta->head      = 0;
149: 
150:     PetscTableAdd(ta,key,data);
151:     /* rehash */
152:     for (ii = 0; ii < tsize; ii++) {
153:       newk = oldkt[ii];
154:       if (newk) {
155:         ndata = oldtab[ii];
156:         PetscTableAdd(ta,newk,ndata);
157:       }
158:     }
159:     if (ta->count != tcount + 1) SETERRQ(PETSC_ERR_COR,"corrupted ta->count");
160: 
161:     PetscFree(oldtab);
162:     PetscFree(oldkt);
163:   }
164:   return(0);
165: }

169: /* PetscTableRemoveAll() ********************************************
170:  *
171:  *
172:  */
173: PetscErrorCode  PetscTableRemoveAll(PetscTable ta)
174: {

178:   ta->head = 0;
179:   if (ta->count) {
180:     ta->count = 0;
181:     PetscMemzero(ta->keytable,ta->tablesize*sizeof(PetscInt));
182:   }
183:   return(0);
184: }

188: /* PetscTableFind() ********************************************
189:  *
190:  * returns data. If data==0, then no table entry exists.
191:  *
192:  */
193: PetscErrorCode  PetscTableFind(PetscTable ta,const PetscInt key,PetscInt *data)
194: {
195:   PetscInt hash,ii = 0;

198:   if (!key) SETERRQ(PETSC_ERR_COR,"Null key");
199:   hash  = HASHT(ta,key);
200:   *data = 0;
201:   while (ii++ < ta->tablesize) {
202:     if (!ta->keytable[hash]) break;
203:     else if (ta->keytable[hash] == key) {
204:       *data = ta->table[hash];
205:       break;
206:     }
207:     hash = (hash == (ta->tablesize-1)) ? 0 : hash+1;
208:   }
209:   return(0);
210: }

214: /* PetscTableGetHeadPosition() ********************************************
215:  *
216:  */
217: PetscErrorCode  PetscTableGetHeadPosition(PetscTable ta,PetscTablePosition *ppos)
218: {
219:   PetscInt i = 0;

222:   *ppos = NULL;
223:   if (!ta->count) return(0);
224: 
225:   /* find first valid place */
226:   do {
227:     if (ta->keytable[i]) {
228:       *ppos = (PetscTablePosition)&ta->table[i];
229:       break;
230:     }
231:   } while (i++ < ta->tablesize);
232:   if (!*ppos) SETERRQ(PETSC_ERR_COR,"No head");
233:   return(0);
234: }

238: /* PetscTableGetNext() ********************************************
239:  *
240:  *  - iteration - PetscTablePosition is always valid (points to a data)
241:  *  
242:  */
243: PetscErrorCode  PetscTableGetNext(PetscTable ta,PetscTablePosition *rPosition,PetscInt *pkey,PetscInt *data)
244: {
245:   PetscInt           idex;
246:   PetscTablePosition pos;

249:   pos = *rPosition;
250:   if (!pos) SETERRQ(PETSC_ERR_COR,"Null position");
251:   *data = *pos;
252:   if (!*data) SETERRQ(PETSC_ERR_COR,"Null data");
253:   idex = pos - ta->table;
254:   *pkey = ta->keytable[idex];
255:   if (!*pkey) SETERRQ(PETSC_ERR_COR,"Null key");

257:   /* get next */
258:   do {
259:     pos++;  idex++;
260:     if (idex >= ta->tablesize) {
261:       pos = 0; /* end of list */
262:       break;
263:     } else if (ta->keytable[idex]) {
264:       pos = ta->table + idex;
265:       break;
266:     }
267:   } while (idex < ta->tablesize);
268:   *rPosition = pos;
269:   return(0);
270: }