/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996-2005 * Sleepycat Software. All rights reserved. * * $Id: db_dup.c,v 12.2 2005/06/16 20:21:10 bostic Exp $ */ #include "db_config.h" #ifndef NO_SYSTEM_INCLUDES #include <sys/types.h> #include <string.h> #endif #include "db_int.h" #include "dbinc/db_page.h" #include "dbinc/db_shash.h" #include "dbinc/mp.h" #include "dbinc/db_am.h" /* * __db_ditem -- * Remove an item from a page. * * PUBLIC: int __db_ditem __P((DBC *, PAGE *, u_int32_t, u_int32_t)); */ int __db_ditem(dbc, pagep, indx, nbytes) DBC *dbc; PAGE *pagep; u_int32_t indx, nbytes; { DB *dbp; DBT ldbt; db_indx_t cnt, *inp, offset; int ret; u_int8_t *from; dbp = dbc->dbp; if (DBC_LOGGING(dbc)) { ldbt.data = P_ENTRY(dbp, pagep, indx); ldbt.size = nbytes; if ((ret = __db_addrem_log(dbp, dbc->txn, &LSN(pagep), 0, DB_REM_DUP, PGNO(pagep), (u_int32_t)indx, nbytes, &ldbt, NULL, &LSN(pagep))) != 0) return (ret); } else LSN_NOT_LOGGED(LSN(pagep)); /* * If there's only a single item on the page, we don't have to * work hard. */ if (NUM_ENT(pagep) == 1) { NUM_ENT(pagep) = 0; HOFFSET(pagep) = dbp->pgsize; return (0); } inp = P_INP(dbp, pagep); /* * Pack the remaining key/data items at the end of the page. Use * memmove(3), the regions may overlap. */ from = (u_int8_t *)pagep + HOFFSET(pagep); DB_ASSERT(inp[indx] >= HOFFSET(pagep)); memmove(from + nbytes, from, inp[indx] - HOFFSET(pagep)); HOFFSET(pagep) += nbytes; /* Adjust the indices' offsets. */ offset = inp[indx]; for (cnt = 0; cnt < NUM_ENT(pagep); ++cnt) if (inp[cnt] < offset) inp[cnt] += nbytes; /* Shift the indices down. */ --NUM_ENT(pagep); if (indx != NUM_ENT(pagep)) memmove(&inp[indx], &inp[indx + 1], sizeof(db_indx_t) * (NUM_ENT(pagep) - indx)); return (0); } /* * __db_pitem -- * Put an item on a page. * * PUBLIC: int __db_pitem * PUBLIC: __P((DBC *, PAGE *, u_int32_t, u_int32_t, DBT *, DBT *)); */ int __db_pitem(dbc, pagep, indx, nbytes, hdr, data) DBC *dbc; PAGE *pagep; u_int32_t indx; u_int32_t nbytes; DBT *hdr, *data; { DB *dbp; BKEYDATA bk; DBT thdr; db_indx_t *inp; int ret; u_int8_t *p; dbp = dbc->dbp; if (nbytes > P_FREESPACE(dbp, pagep)) { DB_ASSERT(nbytes <= P_FREESPACE(dbp, pagep)); return (EINVAL); } /* * Put a single item onto a page. The logic figuring out where to * insert and whether it fits is handled in the caller. All we do * here is manage the page shuffling. We cheat a little bit in that * we don't want to copy the dbt on a normal put twice. If hdr is * NULL, we create a BKEYDATA structure on the page, otherwise, just * copy the caller's information onto the page. * * This routine is also used to put entries onto the page where the * entry is pre-built, e.g., during recovery. In this case, the hdr * will point to the entry, and the data argument will be NULL. * * !!! * There's a tremendous potential for off-by-one errors here, since * the passed in header sizes must be adjusted for the structure's * placeholder for the trailing variable-length data field. */ if (DBC_LOGGING(dbc)) { if ((ret = __db_addrem_log(dbp, dbc->txn, &LSN(pagep), 0, DB_ADD_DUP, PGNO(pagep), (u_int32_t)indx, nbytes, hdr, data, &LSN(pagep))) != 0) return (ret); } else LSN_NOT_LOGGED(LSN(pagep)); if (hdr == NULL) { B_TSET(bk.type, B_KEYDATA, 0); bk.len = data == NULL ? 0 : data->size; thdr.data = &bk; thdr.size = SSZA(BKEYDATA, data); hdr = &thdr; } inp = P_INP(dbp, pagep); /* Adjust the index table, then put the item on the page. */ if (indx != NUM_ENT(pagep)) memmove(&inp[indx + 1], &inp[indx], sizeof(db_indx_t) * (NUM_ENT(pagep) - indx)); HOFFSET(pagep) -= nbytes; inp[indx] = HOFFSET(pagep); ++NUM_ENT(pagep); p = P_ENTRY(dbp, pagep, indx); memcpy(p, hdr->data, hdr->size); if (data != NULL) memcpy(p + hdr->size, data->data, data->size); return (0); }