ceph/src/key_value_store/cls_kvs.cc

   1 /*
   2  * OSD classes for the key value store
   3  *
   4  *  Created on: Aug 10, 2012
   5  *      Author: Eleanor Cawthon
   6  */
   7
   8 #include "objclass/objclass.h"
   9 #include <errno.h>
  10 #include "key_value_store/kvs_arg_types.h"
  11 #include "include/types.h"
  12 #include <iostream>
  13 #include <climits>
  14
  15
  16 /**
  17  * finds the index_data where a key belongs.
  18  *
  19  * @param key: the key to search for
  20  * @param idata: the index_data for the first index value such that idata.key
  21  * is greater than key.
  22  * @param next_idata: the index_data for the next index entry after idata
  23  * @pre: key is not encoded
  24  * @post: idata contains complete information
  25  * stored
  26  */
  27 static int get_idata_from_key(cls_method_context_t hctx, const string &key,
  28     index_data &idata, index_data &next_idata) {
  29   bufferlist raw_val;
  30   int r = 0;
  31   std::map<std::string, bufferlist> kvmap;
  32
  33   bool more;
  34
  35   r = cls_cxx_map_get_vals(hctx, key_data(key).encoded(), "", 2, &kvmap, &more);
  36   if (r < 0) {
  37     CLS_LOG(20, "error reading index for range %s: %d", key.c_str(), r);
  38     return r;
  39   }
  40
  41   r = cls_cxx_map_get_val(hctx, key_data(key).encoded(), &raw_val);
  42   if (r == 0){
  43     CLS_LOG(20, "%s is already in the index: %d", key.c_str(), r);
  44     bufferlist::iterator b = raw_val.begin();
  45     idata.decode(b);
  46     if (!kvmap.empty()) {
  47       bufferlist::iterator b = kvmap.begin()->second.begin();
  48       next_idata.decode(b);
  49     }
  50     return r;
  51   } else if (r == -ENOENT || r == -ENODATA) {
  52     bufferlist::iterator b = kvmap.begin()->second.begin();
  53     idata.decode(b);
  54     if (idata.kdata.prefix != "1") {
  55       bufferlist::iterator nb = (++kvmap.begin())->second.begin();
  56       next_idata.decode(nb);
  57     }
  58     r = 0;
  59   } else if (r < 0) {
  60     CLS_LOG(20, "error reading index for duplicates %s: %d", key.c_str(), r);
  61     return r;
  62   }
  63
  64   CLS_LOG(20, "idata is %s", idata.str().c_str());
  65   return r;
  66 }
  67
  68
  69 static int get_idata_from_key_op(cls_method_context_t hctx,
  70                    bufferlist *in, bufferlist *out) {
  71   CLS_LOG(20, "get_idata_from_key_op");
  72   idata_from_key_args op;
  73   bufferlist::iterator it = in->begin();
  74   try {
  75     ::decode(op, it);
  76   } catch (buffer::error& err) {
  77     CLS_LOG(20, "error decoding idata_from_key_args.");
  78     return -EINVAL;
  79   }
  80   int r = get_idata_from_key(hctx, op.key, op.idata, op.next_idata);
  81   if (r < 0) {
  82     return r;
  83   } else {
  84     ::encode(op, *out);
  85     return 0;
  86   }
  87 }
  88
  89 /**
  90  * finds the object in the index with the lowest key value that is greater
  91  * than idata.key. If idata.key is the max key, returns -EOVERFLOW. If
  92  * idata has a prefix and has timed out, cleans up.
  93  *
  94  * @param idata: idata for the object to search for.
  95  * @param out_data: the idata for the next object.
  96  *
  97  * @pre: idata must contain a key.
  98  * @post: out_data contains complete information
  99  */
 100 static int get_next_idata(cls_method_context_t hctx, const index_data &idata,
 101     index_data &out_data) {
 102   int r = 0;
 103   std::map<std::string, bufferlist> kvs;
 104   bool more;
 105   r = cls_cxx_map_get_vals(hctx, idata.kdata.encoded(), "", 1, &kvs, &more);
 106   if (r < 0){
 107     CLS_LOG(20, "getting kvs failed with error %d", r);
 108     return r;
 109   }
 110
 111   if (!kvs.empty()) {
 112     out_data.kdata.parse(kvs.begin()->first);
 113     bufferlist::iterator b = kvs.begin()->second.begin();
 114     out_data.decode(b);
 115   } else {
 116     r = -EOVERFLOW;
 117   }
 118
 119   return r;
 120 }
 121
 122 static int get_next_idata_op(cls_method_context_t hctx,
 123                    bufferlist *in, bufferlist *out) {
 124   CLS_LOG(20, "get_next_idata_op");
 125   idata_from_idata_args op;
 126   bufferlist::iterator it = in->begin();
 127   try {
 128     ::decode(op, it);
 129   } catch (buffer::error& err) {
 130     return -EINVAL;
 131   }
 132   int r = get_next_idata(hctx, op.idata, op.next_idata);
 133   if (r < 0) {
 134     return r;
 135   } else {
 136     op.encode(*out);
 137     return 0;
 138   }
 139 }
 140
 141 /**
 142  * finds the object in the index with the highest key value that is less
 143  * than idata.key. If idata.key is the lowest key, returns -ERANGE If
 144  * idata has a prefix and has timed out, cleans up.
 145  *
 146  * @param idata: idata for the object to search for.
 147  * @param out_data: the idata for the next object.
 148  *
 149  * @pre: idata must contain a key.
 150  * @ost: out_data contains complete information
 151  */
 152 static int get_prev_idata(cls_method_context_t hctx, const index_data &idata,
 153     index_data &out_data) {
 154   int r = 0;
 155   std::map<std::string, bufferlist> kvs;
 156   bool more;
 157   r = cls_cxx_map_get_vals(hctx, "", "", LONG_MAX, &kvs, &more);
 158   if (r < 0){
 159     CLS_LOG(20, "getting kvs failed with error %d", r);
 160     return r;
 161   }
 162
 163   std::map<std::string, bufferlist>::iterator it =
 164       kvs.lower_bound(idata.kdata.encoded());
 165   if (it->first != idata.kdata.encoded()) {
 166     CLS_LOG(20, "object %s not found in the index (expected %s, found %s)",
 167         idata.str().c_str(), idata.kdata.encoded().c_str(),
 168         it->first.c_str());
 169     return -ENODATA;
 170   }
 171   if (it == kvs.begin()) {
 172     //it is the first object, there is no previous.
 173     return -ERANGE;
 174   } else {
 175     --it;
 176   }
 177   out_data.kdata.parse(it->first);
 178   bufferlist::iterator b = it->second.begin();
 179   out_data.decode(b);
 180
 181   return 0;
 182 }
 183
 184 static int get_prev_idata_op(cls_method_context_t hctx,
 185                    bufferlist *in, bufferlist *out) {
 186   CLS_LOG(20, "get_next_idata_op");
 187   idata_from_idata_args op;
 188   bufferlist::iterator it = in->begin();
 189   try {
 190     ::decode(op, it);
 191   } catch (buffer::error& err) {
 192     return -EINVAL;
 193   }
 194   int r = get_prev_idata(hctx, op.idata, op.next_idata);
 195   if (r < 0) {
 196     return r;
 197   } else {
 198     op.encode(*out);
 199     return 0;
 200   }
 201 }
 202
 203 /**
 204  * Read all of the index entries where any keys in the map go
 205  */
 206 static int read_many(cls_method_context_t hctx, const set<string> &keys,
 207     map<string, bufferlist> * out) {
 208   int r = 0;
 209   bool more;
 210   CLS_ERR("reading from a map of size %d, first key encoded is %s",
 211       (int)keys.size(), key_data(*keys.begin()).encoded().c_str());
 212   r = cls_cxx_map_get_vals(hctx, key_data(*keys.begin()).encoded().c_str(),
 213       "", LONG_MAX, out, &more);
 214   if (r < 0) {
 215     CLS_ERR("getting omap vals failed with error %d", r);
 216   }
 217
 218   CLS_ERR("got map of size %d ", (int)out->size());
 219   if (out->size() > 1) {
 220     out->erase(out->upper_bound(key_data(*keys.rbegin()).encoded().c_str()),
 221       out->end());
 222   }
 223   CLS_ERR("returning map of size %d", (int)out->size());
 224   return r;
 225 }
 226
 227 static int read_many_op(cls_method_context_t hctx, bufferlist *in,
 228     bufferlist *out) {
 229   CLS_LOG(20, "read_many_op");
 230   set<string> op;
 231   map<string, bufferlist> outmap;
 232   bufferlist::iterator it = in->begin();
 233   try {
 234     ::decode(op, it);
 235   } catch (buffer::error & err) {
 236     return -EINVAL;
 237   }
 238   int r = read_many(hctx, op, &outmap);
 239   if (r < 0) {
 240     return r;
 241   } else {
 242     encode(outmap, *out);
 243     return 0;
 244   }
 245 }
 246
 247 /**
 248  * Checks the unwritable xattr. If it is "1" (i.e., it is unwritable), returns
 249  * -EACCES. otherwise, returns 0.
 250  */
 251 static int check_writable(cls_method_context_t hctx) {
 252   bufferlist bl;
 253   int r = cls_cxx_getxattr(hctx, "unwritable", &bl);
 254   if (r < 0) {
 255     CLS_LOG(20, "error reading xattr %s: %d", "unwritable", r);
 256     return r;
 257   }
 258   if (string(bl.c_str(), bl.length()) == "1") {
 259     return -EACCES;
 260   } else{
 261     return 0;
 262   }
 263 }
 264
 265 static int check_writable_op(cls_method_context_t hctx,
 266                    bufferlist *in, bufferlist *out) {
 267   CLS_LOG(20, "check_writable_op");
 268   return check_writable(hctx);
 269 }
 270
 271 /**
 272  * returns -EKEYREJECTED if size is outside of bound, according to comparator.
 273  *
 274  * @bound: the limit to test
 275  * @comparator: should be CEPH_OSD_CMPXATTR_OP_[EQ|GT|LT]
 276  */
 277 static int assert_size_in_bound(cls_method_context_t hctx, int bound,
 278     int comparator) {
 279   //determine size
 280   bufferlist size_bl;
 281   int r = cls_cxx_getxattr(hctx, "size", &size_bl);
 282   if (r < 0) {
 283     CLS_LOG(20, "error reading xattr %s: %d", "size", r);
 284     return r;
 285   }
 286
 287   int size = atoi(string(size_bl.c_str(), size_bl.length()).c_str());
 288   CLS_LOG(20, "size is %d, bound is %d", size, bound);
 289
 290   //compare size to comparator
 291   switch (comparator) {
 292   case CEPH_OSD_CMPXATTR_OP_EQ:
 293     if (size != bound) {
 294       return -EKEYREJECTED;
 295     }
 296     break;
 297   case CEPH_OSD_CMPXATTR_OP_LT:
 298     if (size >= bound) {
 299       return -EKEYREJECTED;
 300     }
 301     break;
 302   case CEPH_OSD_CMPXATTR_OP_GT:
 303     if (size <= bound) {
 304       return -EKEYREJECTED;
 305     }
 306     break;
 307   default:
 308     CLS_LOG(20, "invalid argument passed to assert_size_in_bound: %d",
 309             comparator);
 310     return -EINVAL;
 311   }
 312   return 0;
 313 }
 314
 315 static int assert_size_in_bound_op(cls_method_context_t hctx,
 316                    bufferlist *in, bufferlist *out) {
 317   CLS_LOG(20, "assert_size_in_bound_op");
 318   assert_size_args op;
 319   bufferlist::iterator it = in->begin();
 320   try {
 321     ::decode(op, it);
 322   } catch (buffer::error& err) {
 323     return -EINVAL;
 324   }
 325   return assert_size_in_bound(hctx, op.bound, op.comparator);
 326 }
 327
 328 /**
 329  * Attempts to insert omap into this object's omap.
 330  *
 331  * @return:
 332  * if unwritable, returns -EACCES.
 333  * if size > bound and key doesn't already exist in the omap, returns -EBALANCE.
 334  * if exclusive is true, returns -EEXIST if any keys already exist.
 335  *
 336  * @post: object has omap entries inserted, and size xattr is updated
 337  */
 338 static int omap_insert(cls_method_context_t hctx,
 339     const map<string, bufferlist> &omap, int bound, bool exclusive) {
 340
 341   uint64_t size;
 342   time_t time;
 343   int r = cls_cxx_stat(hctx, &size, &time);
 344   if (r < 0) {
 345     return r;
 346   }
 347   CLS_LOG(20, "inserting %s", omap.begin()->first.c_str());
 348   r = check_writable(hctx);
 349   if (r < 0) {
 350     CLS_LOG(20, "omap_insert: this object is unwritable: %d", r);
 351     return r;
 352   }
 353
 354   int assert_bound = bound;
 355
 356   //if this is an exclusive insert, make sure the key doesn't already exist.
 357   for (map<string, bufferlist>::const_iterator it = omap.begin();
 358       it != omap.end(); ++it) {
 359     bufferlist bl;
 360     r = cls_cxx_map_get_val(hctx, it->first, &bl);
 361     if (r == 0 && string(bl.c_str(), bl.length()) != ""){
 362       if (exclusive) {
 363         CLS_LOG(20, "error: this is an exclusive insert and %s exists.",
 364             it->first.c_str());
 365         return -EEXIST;
 366       }
 367       assert_bound++;
 368       CLS_LOG(20, "increased assert_bound to %d", assert_bound);
 369     } else if (r != -ENODATA && r != -ENOENT) {
 370       CLS_LOG(20, "error reading omap val for %s: %d", it->first.c_str(), r);
 371       return r;
 372     }
 373   }
 374
 375   bufferlist old_size;
 376   r = cls_cxx_getxattr(hctx, "size", &old_size);
 377   if (r < 0) {
 378     CLS_LOG(20, "error reading xattr %s: %d", "size", r);
 379     return r;
 380   }
 381
 382   int old_size_int = atoi(string(old_size.c_str(), old_size.length()).c_str());
 383
 384   CLS_LOG(20, "asserting size is less than %d (bound is %d)", assert_bound, bound);
 385   if (old_size_int >= assert_bound) {
 386     return -EKEYREJECTED;
 387   }
 388
 389   int new_size_int = old_size_int + omap.size() - (assert_bound - bound);
 390   CLS_LOG(20, "old size is %d, new size is %d", old_size_int, new_size_int);
 391   bufferlist new_size;
 392   stringstream s;
 393   s << new_size_int;
 394   new_size.append(s.str());
 395
 396   r = cls_cxx_map_set_vals(hctx, &omap);
 397   if (r < 0) {
 398     CLS_LOG(20, "error setting omap: %d", r);
 399     return r;
 400   }
 401
 402   r = cls_cxx_setxattr(hctx, "size", &new_size);
 403   if (r < 0) {
 404     CLS_LOG(20, "error setting xattr %s: %d", "size", r);
 405     return r;
 406   }
 407   CLS_LOG(20, "successfully inserted %s", omap.begin()->first.c_str());
 408   return 0;
 409 }
 410
 411 static int omap_insert_op(cls_method_context_t hctx,
 412                    bufferlist *in, bufferlist *out) {
 413   CLS_LOG(20, "omap_insert");
 414   omap_set_args op;
 415   bufferlist::iterator it = in->begin();
 416   try {
 417     ::decode(op, it);
 418   } catch (buffer::error& err) {
 419     return -EINVAL;
 420   }
 421   return omap_insert(hctx, op.omap, op.bound, op.exclusive);
 422 }
 423
 424 static int create_with_omap(cls_method_context_t hctx,
 425     const map<string, bufferlist> &omap) {
 426   CLS_LOG(20, "creating with omap: %s", omap.begin()->first.c_str());
 427   //first make sure the object is writable
 428   int r = cls_cxx_create(hctx, true);
 429   if (r < 0) {
 430     CLS_LOG(20, "omap create: creating failed: %d", r);
 431     return r;
 432   }
 433
 434   int new_size_int = omap.size();
 435   CLS_LOG(20, "omap insert: new size is %d", new_size_int);
 436   bufferlist new_size;
 437   stringstream s;
 438   s << new_size_int;
 439   new_size.append(s.str());
 440
 441   r = cls_cxx_map_set_vals(hctx, &omap);
 442   if (r < 0) {
 443     CLS_LOG(20, "omap create: error setting omap: %d", r);
 444     return r;
 445   }
 446
 447   r = cls_cxx_setxattr(hctx, "size", &new_size);
 448   if (r < 0) {
 449     CLS_LOG(20, "omap create: error setting xattr %s: %d", "size", r);
 450     return r;
 451   }
 452
 453   bufferlist u;
 454   u.append("0");
 455   r = cls_cxx_setxattr(hctx, "unwritable", &u);
 456   if (r < 0) {
 457     CLS_LOG(20, "omap create: error setting xattr %s: %d", "unwritable", r);
 458     return r;
 459   }
 460
 461   CLS_LOG(20, "successfully created %s", omap.begin()->first.c_str());
 462   return 0;
 463 }
 464
 465 static int create_with_omap_op(cls_method_context_t hctx,
 466                    bufferlist *in, bufferlist *out) {
 467   CLS_LOG(20, "omap_insert");
 468   map<string, bufferlist> omap;
 469   bufferlist::iterator it = in->begin();
 470   try {
 471     ::decode(omap, it);
 472   } catch (buffer::error& err) {
 473     return -EINVAL;
 474   }
 475   return create_with_omap(hctx, omap);
 476 }
 477
 478 /**
 479  * Attempts to remove omap from this object's omap.
 480  *
 481  * @return:
 482  * if unwritable, returns -EACCES.
 483  * if size < bound and key doesn't already exist in the omap, returns -EBALANCE.
 484  * if any of the keys are not in this object, returns -ENODATA.
 485  *
 486  * @post: object has omap entries removed, and size xattr is updated
 487  */
 488 static int omap_remove(cls_method_context_t hctx,
 489     const std::set<string> &omap, int bound) {
 490   int r;
 491   uint64_t size;
 492   time_t time;
 493   r = cls_cxx_stat(hctx, &size, &time);
 494   if (r < 0) {
 495     return r;
 496   }
 497
 498   //first make sure the object is writable
 499   r = check_writable(hctx);
 500   if (r < 0) {
 501     return r;
 502   }
 503
 504   //check for existance of the key first
 505   for (set<string>::const_iterator it = omap.begin();
 506       it != omap.end(); ++it) {
 507     bufferlist bl;
 508     r = cls_cxx_map_get_val(hctx, *it, &bl);
 509     if (r == -ENOENT || r == -ENODATA
 510         || string(bl.c_str(), bl.length()) == ""){
 511       return -ENODATA;
 512     } else if (r < 0) {
 513       CLS_LOG(20, "error reading omap val for %s: %d", it->c_str(), r);
 514       return r;
 515     }
 516   }
 517
 518   //fail if removing from an object with only bound entries.
 519   bufferlist old_size;
 520   r = cls_cxx_getxattr(hctx, "size", &old_size);
 521   if (r < 0) {
 522     CLS_LOG(20, "error reading xattr %s: %d", "size", r);
 523     return r;
 524   }
 525   int old_size_int = atoi(string(old_size.c_str(), old_size.length()).c_str());
 526
 527   CLS_LOG(20, "asserting size is greater than %d", bound);
 528   if (old_size_int <= bound) {
 529     return -EKEYREJECTED;
 530   }
 531
 532   int new_size_int = old_size_int - omap.size();
 533   CLS_LOG(20, "old size is %d, new size is %d", old_size_int, new_size_int);
 534   bufferlist new_size;
 535   stringstream s;
 536   s << new_size_int;
 537   new_size.append(s.str());
 538
 539   r = cls_cxx_setxattr(hctx, "size", &new_size);
 540   if (r < 0) {
 541     CLS_LOG(20, "error setting xattr %s: %d", "unwritable", r);
 542     return r;
 543   }
 544
 545   for (std::set<string>::const_iterator it = omap.begin();
 546       it != omap.end(); ++it) {
 547     r = cls_cxx_map_remove_key(hctx, *it);
 548     if (r < 0) {
 549       CLS_LOG(20, "error removing omap: %d", r);
 550       return r;
 551     }
 552   }
 553   return 0;
 554 }
 555
 556 static int omap_remove_op(cls_method_context_t hctx,
 557                    bufferlist *in, bufferlist *out) {
 558   CLS_LOG(20, "omap_remove");
 559   omap_rm_args op;
 560   bufferlist::iterator it = in->begin();
 561   try {
 562     ::decode(op, it);
 563   } catch (buffer::error& err) {
 564     return -EINVAL;
 565   }
 566   return omap_remove(hctx, op.omap, op.bound);
 567 }
 568
 569 /**
 570  * checks to see if this object needs to be split or rebalanced. if so, reads
 571  * information about it.
 572  *
 573  * @post: if assert_size_in_bound(hctx, bound, comparator) succeeds,
 574  * odata contains the size, omap, and unwritable attributes for this object.
 575  * Otherwise, odata contains the size and unwritable attribute.
 576  */
 577 static int maybe_read_for_balance(cls_method_context_t hctx,
 578     object_data &odata, int bound, int comparator) {
 579   CLS_LOG(20, "rebalance reading");
 580   //if unwritable, return
 581   int r = check_writable(hctx);
 582   if (r < 0) {
 583     odata.unwritable = true;
 584     CLS_LOG(20, "rebalance read: error getting xattr %s: %d", "unwritable", r);
 585     return r;
 586   } else {
 587     odata.unwritable = false;
 588   }
 589
 590   //get the size attribute
 591   bufferlist size;
 592   r = cls_cxx_getxattr(hctx, "size", &size);
 593   if (r < 0) {
 594     CLS_LOG(20, "rebalance read: error getting xattr %s: %d", "size", r);
 595     return r;
 596   }
 597   odata.size = atoi(string(size.c_str(), size.length()).c_str());
 598
 599   //check if it needs to be balanced
 600   r = assert_size_in_bound(hctx, bound, comparator);
 601   if (r < 0) {
 602     CLS_LOG(20, "rebalance read: error on asserting size: %d", r);
 603     return -EBALANCE;
 604   }
 605
 606   //if the assert succeeded, it needs to be balanced
 607   bool more;
 608   r = cls_cxx_map_get_vals(hctx, "", "", LONG_MAX, &odata.omap, &more);
 609   if (r < 0){
 610     CLS_LOG(20, "rebalance read: getting kvs failed with error %d", r);
 611     return r;
 612   }
 613
 614   CLS_LOG(20, "rebalance read: size xattr is %llu, omap size is %llu",
 615           (unsigned long long)odata.size,
 616           (unsigned long long)odata.omap.size());
 617   return 0;
 618 }
 619
 620 static int maybe_read_for_balance_op(cls_method_context_t hctx,
 621                    bufferlist *in, bufferlist *out) {
 622   CLS_LOG(20, "maybe_read_for_balance");
 623   rebalance_args op;
 624   bufferlist::iterator it = in->begin();
 625   try {
 626     ::decode(op, it);
 627   } catch (buffer::error& err) {
 628     return -EINVAL;
 629   }
 630   int r = maybe_read_for_balance(hctx, op.odata, op.bound, op.comparator);
 631   if (r < 0) {
 632     return r;
 633   } else {
 634     op.encode(*out);
 635     return 0;
 636   }
 637 }
 638
 639
 640 CLS_INIT(kvs)
 641 {
 642   CLS_LOG(20, "Loaded assert condition class!");
 643
 644   cls_handle_t h_class;
 645   cls_method_handle_t h_get_idata_from_key;
 646   cls_method_handle_t h_get_next_idata;
 647   cls_method_handle_t h_get_prev_idata;
 648   cls_method_handle_t h_read_many;
 649   cls_method_handle_t h_check_writable;
 650   cls_method_handle_t h_assert_size_in_bound;
 651   cls_method_handle_t h_omap_insert;
 652   cls_method_handle_t h_create_with_omap;
 653   cls_method_handle_t h_omap_remove;
 654   cls_method_handle_t h_maybe_read_for_balance;
 655
 656   cls_register("kvs", &h_class);
 657   cls_register_cxx_method(h_class, "get_idata_from_key",
 658                           CLS_METHOD_RD,
 659                           get_idata_from_key_op, &h_get_idata_from_key);
 660   cls_register_cxx_method(h_class, "get_next_idata",
 661                           CLS_METHOD_RD,
 662                           get_next_idata_op, &h_get_next_idata);
 663   cls_register_cxx_method(h_class, "get_prev_idata",
 664                           CLS_METHOD_RD,
 665                           get_prev_idata_op, &h_get_prev_idata);
 666   cls_register_cxx_method(h_class, "read_many",
 667                           CLS_METHOD_RD,
 668                           read_many_op, &h_read_many);
 669   cls_register_cxx_method(h_class, "check_writable",
 670                           CLS_METHOD_RD | CLS_METHOD_WR,
 671                           check_writable_op, &h_check_writable);
 672   cls_register_cxx_method(h_class, "assert_size_in_bound",
 673                           CLS_METHOD_WR,
 674                           assert_size_in_bound_op, &h_assert_size_in_bound);
 675   cls_register_cxx_method(h_class, "omap_insert",
 676                           CLS_METHOD_WR,
 677                           omap_insert_op, &h_omap_insert);
 678   cls_register_cxx_method(h_class, "create_with_omap",
 679                           CLS_METHOD_WR,
 680                           create_with_omap_op, &h_create_with_omap);
 681   cls_register_cxx_method(h_class, "omap_remove",
 682                           CLS_METHOD_WR,
 683                           omap_remove_op, &h_omap_remove);
 684   cls_register_cxx_method(h_class, "maybe_read_for_balance",
 685                           CLS_METHOD_RD,
 686                           maybe_read_for_balance_op, &h_maybe_read_for_balance);
 687
 688   return;
 689 }