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Diffstat (limited to 'ext/kissdb/kissdb.h')
| -rw-r--r-- | ext/kissdb/kissdb.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/ext/kissdb/kissdb.h b/ext/kissdb/kissdb.h new file mode 100644 index 00000000..b4e87954 --- /dev/null +++ b/ext/kissdb/kissdb.h @@ -0,0 +1,171 @@ +/* (Keep It) Simple Stupid Database + * + * Written by Adam Ierymenko <adam.ierymenko@zerotier.com> + * KISSDB is in the public domain and is distributed with NO WARRANTY. */ + +#ifndef ___KISSDB_H +#define ___KISSDB_H + +#include <stdio.h> +#include <stdint.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * Version: 2 + * + * This is the file format identifier, and changes any time the file + * format changes. The code version will be this dot something, and can + * be seen in tags in the git repository. + */ +#define KISSDB_VERSION 2 + +/** + * KISSDB database state + * + * These fields can be read by a user, e.g. to look up key_size and + * value_size, but should never be changed. + */ +typedef struct { + unsigned long hash_table_size; + unsigned long key_size; + unsigned long value_size; + unsigned long hash_table_size_bytes; + unsigned long num_hash_tables; + uint64_t *hash_tables; + FILE *f; +} KISSDB; + +/** + * I/O error or file not found + */ +#define KISSDB_ERROR_IO -1 + +/** + * Out of memory + */ +#define KISSDB_ERROR_MALLOC -2 + +/** + * Invalid paramters (e.g. missing _size paramters on init to create database) + */ +#define KISSDB_ERROR_INVALID_PARAMETERS -3 + +/** + * Database file appears corrupt + */ +#define KISSDB_ERROR_CORRUPT_DBFILE -4 + +/** + * Open mode: read only + */ +#define KISSDB_OPEN_MODE_RDONLY 1 + +/** + * Open mode: read/write + */ +#define KISSDB_OPEN_MODE_RDWR 2 + +/** + * Open mode: read/write, create if doesn't exist + */ +#define KISSDB_OPEN_MODE_RWCREAT 3 + +/** + * Open mode: truncate database, open for reading and writing + */ +#define KISSDB_OPEN_MODE_RWREPLACE 4 + +/** + * Open database + * + * The three _size parameters must be specified if the database could + * be created or re-created. Otherwise an error will occur. If the + * database already exists, these parameters are ignored and are read + * from the database. You can check the struture afterwords to see what + * they were. + * + * @param db Database struct + * @param path Path to file + * @param mode One of the KISSDB_OPEN_MODE constants + * @param hash_table_size Size of hash table in 64-bit entries (must be >0) + * @param key_size Size of keys in bytes + * @param value_size Size of values in bytes + * @return 0 on success, nonzero on error + */ +extern int KISSDB_open( + KISSDB *db, + const char *path, + int mode, + unsigned long hash_table_size, + unsigned long key_size, + unsigned long value_size); + +/** + * Close database + * + * @param db Database struct + */ +extern void KISSDB_close(KISSDB *db); + +/** + * Get an entry + * + * @param db Database struct + * @param key Key (key_size bytes) + * @param vbuf Value buffer (value_size bytes capacity) + * @return -1 on I/O error, 0 on success, 1 on not found + */ +extern int KISSDB_get(KISSDB *db,const void *key,void *vbuf); + +/** + * Put an entry (overwriting it if it already exists) + * + * In the already-exists case the size of the database file does not + * change. + * + * @param db Database struct + * @param key Key (key_size bytes) + * @param value Value (value_size bytes) + * @return -1 on I/O error, 0 on success + */ +extern int KISSDB_put(KISSDB *db,const void *key,const void *value); + +/** + * Cursor used for iterating over all entries in database + */ +typedef struct { + KISSDB *db; + unsigned long h_no; + unsigned long h_idx; +} KISSDB_Iterator; + +/** + * Initialize an iterator + * + * @param db Database struct + * @param i Iterator to initialize + */ +extern void KISSDB_Iterator_init(KISSDB *db,KISSDB_Iterator *dbi); + +/** + * Get the next entry + * + * The order of entries returned by iterator is undefined. It depends on + * how keys hash. + * + * @param Database iterator + * @param kbuf Buffer to fill with next key (key_size bytes) + * @param vbuf Buffer to fill with next value (value_size bytes) + * @return 0 if there are no more entries, negative on error, positive if an kbuf/vbuf have been filled + */ +extern int KISSDB_Iterator_next(KISSDB_Iterator *dbi,void *kbuf,void *vbuf); + +#ifdef __cplusplus +} +#endif + +#endif + |