Shows how to extend WiredTiger with application-specific collations, extractors and cursor types.
/*- * Copyright (c) 2008-2012 WiredTiger, Inc. * * This is free and unencumbered software released into the public domain. * * Anyone is free to copy, modify, publish, use, compile, sell, or * distribute this software, either in source code form or as a compiled * binary, for any purpose, commercial or non-commercial, and by any * means. * * In jurisdictions that recognize copyright laws, the author or authors * of this software dedicate any and all copyright interest in the * software to the public domain. We make this dedication for the benefit * of the public at large and to the detriment of our heirs and * successors. We intend this dedication to be an overt act of * relinquishment in perpetuity of all present and future rights to this * software under copyright law. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. * * ex_extending.c * This is an example demonstrating ways to extend WiredTiger with * extractors, collators and loadable modules. */ #include <stdio.h> #include <string.h> #include <wiredtiger.h> const char *home = "WT_TEST"; /* A simple case insensitive comparator. */ static int __compare_nocase(WT_COLLATOR *collator, WT_SESSION *session, const WT_ITEM *v1, const WT_ITEM *v2, int *cmp) { const char *s1 = (const char *)v1->data; const char *s2 = (const char *)v2->data; (void)session; /* unused */ (void)collator; /* unused */ *cmp = strcasecmp(s1, s2); return (0); } static WT_COLLATOR nocasecoll = { __compare_nocase }; /* * Comparator that only compares the first N prefix characters of the string. * This has associated data, so we need to extend WT_COLLATOR. */ typedef struct { WT_COLLATOR iface; uint32_t maxlen; } PREFIX_COLLATOR; static int __compare_prefixes(WT_COLLATOR *collator, WT_SESSION *session, const WT_ITEM *v1, const WT_ITEM *v2, int *cmp) { PREFIX_COLLATOR *pcoll = (PREFIX_COLLATOR *)collator; const char *s1 = (const char *)v1->data; const char *s2 = (const char *)v2->data; (void)session; /* unused */ *cmp = strncmp(s1, s2, pcoll->maxlen); return (0); } static PREFIX_COLLATOR pcoll10 = { {__compare_prefixes}, 10 }; int main(void) { int ret; WT_CONNECTION *conn; WT_SESSION *session; /* Open a connection to the database, creating it if necessary. */ if ((ret = wiredtiger_open(home, NULL, "create", &conn)) != 0) fprintf(stderr, "Error connecting to %s: %s\n", home, wiredtiger_strerror(ret)); ret = conn->add_collator(conn, "nocase", &nocasecoll, NULL); ret = conn->add_collator(conn, "prefix10", &pcoll10.iface, NULL); /* Open a session for the current thread's work. */ if ((ret = conn->open_session(conn, NULL, NULL, &session)) != 0) fprintf(stderr, "Error opening a session on %s: %s\n", home, wiredtiger_strerror(ret)); /* XXX Do some work... */ /* Note: closing the connection implicitly closes open session(s). */ if ((ret = conn->close(conn, NULL)) != 0) fprintf(stderr, "Error connecting to %s: %s\n", home, wiredtiger_strerror(ret)); return (ret); }