diff options
Diffstat (limited to 'lib/tdb2/private.h')
| -rw-r--r-- | lib/tdb2/private.h | 624 |
1 files changed, 624 insertions, 0 deletions
diff --git a/lib/tdb2/private.h b/lib/tdb2/private.h new file mode 100644 index 0000000000..0c3e441657 --- /dev/null +++ b/lib/tdb2/private.h @@ -0,0 +1,624 @@ +#ifndef TDB_PRIVATE_H +#define TDB_PRIVATE_H + /* + Trivial Database 2: private types and prototypes + Copyright (C) Rusty Russell 2010 + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 3 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, see <http://www.gnu.org/licenses/>. +*/ + +#include "config.h" +#if HAVE_FILE_OFFSET_BITS +#define _FILE_OFFSET_BITS 64 +#endif +#include <ccan/likely/likely.h> +#include <ccan/compiler/compiler.h> +#include <ccan/endian/endian.h> +#include "tdb2.h" + +#ifdef _SAMBA_BUILD_ +#include "replace.h" +#include "system/filesys.h" +#include "system/time.h" +#include "system/shmem.h" +#include "system/select.h" +#include "system/wait.h" +#else +#include <stdint.h> +#include <stdbool.h> +#include <stdlib.h> +#include <stddef.h> +#include <sys/time.h> +#include <sys/mman.h> +#include <unistd.h> +#include <fcntl.h> +#include <string.h> +#include <errno.h> +#include <stdio.h> +#include <utime.h> +#include <unistd.h> +#endif + +#ifndef TEST_IT +#define TEST_IT(cond) +#endif + +/* #define TDB_TRACE 1 */ + +#ifndef __STRING +#define __STRING(x) #x +#endif + +#ifndef __STRINGSTRING +#define __STRINGSTRING(x) __STRING(x) +#endif + +#ifndef __location__ +#define __location__ __FILE__ ":" __STRINGSTRING(__LINE__) +#endif + +typedef uint64_t tdb_len_t; +typedef uint64_t tdb_off_t; + +#define TDB_MAGIC_FOOD "TDB file\n" +#define TDB_VERSION ((uint64_t)(0x26011967 + 7)) +#define TDB_USED_MAGIC ((uint64_t)0x1999) +#define TDB_HTABLE_MAGIC ((uint64_t)0x1888) +#define TDB_CHAIN_MAGIC ((uint64_t)0x1777) +#define TDB_FTABLE_MAGIC ((uint64_t)0x1666) +#define TDB_FREE_MAGIC ((uint64_t)0xFE) +#define TDB_HASH_MAGIC (0xA1ABE11A01092008ULL) +#define TDB_RECOVERY_MAGIC (0xf53bc0e7ad124589ULL) +#define TDB_RECOVERY_INVALID_MAGIC (0x0ULL) + +#define TDB_OFF_IS_ERR(off) unlikely(off >= (tdb_off_t)TDB_ERR_LAST) + +/* Packing errors into pointers and v.v. */ +#define TDB_PTR_IS_ERR(ptr) \ + unlikely((unsigned long)(ptr) >= (unsigned long)TDB_ERR_LAST) +#define TDB_PTR_ERR(p) ((enum TDB_ERROR)(long)(p)) +#define TDB_ERR_PTR(err) ((void *)(long)(err)) + +/* Common case of returning true, false or -ve error. */ +typedef int tdb_bool_err; + +/* Prevent others from opening the file. */ +#define TDB_OPEN_LOCK 0 +/* Doing a transaction. */ +#define TDB_TRANSACTION_LOCK 1 +/* Expanding file. */ +#define TDB_EXPANSION_LOCK 2 +/* Hash chain locks. */ +#define TDB_HASH_LOCK_START 64 + +/* Range for hash locks. */ +#define TDB_HASH_LOCK_RANGE_BITS 30 +#define TDB_HASH_LOCK_RANGE (1 << TDB_HASH_LOCK_RANGE_BITS) + +/* We have 1024 entries in the top level. */ +#define TDB_TOPLEVEL_HASH_BITS 10 +/* And 64 entries in each sub-level: thus 64 bits exactly after 9 levels. */ +#define TDB_SUBLEVEL_HASH_BITS 6 +/* And 8 entries in each group, ie 8 groups per sublevel. */ +#define TDB_HASH_GROUP_BITS 3 +/* This is currently 10: beyond this we chain. */ +#define TDB_MAX_LEVELS (1+(64-TDB_TOPLEVEL_HASH_BITS) / TDB_SUBLEVEL_HASH_BITS) + +/* Extend file by least 100 times larger than needed. */ +#define TDB_EXTENSION_FACTOR 100 + +/* We steal bits from the offsets to store hash info. */ +#define TDB_OFF_HASH_GROUP_MASK ((1ULL << TDB_HASH_GROUP_BITS) - 1) +/* We steal this many upper bits, giving a maximum offset of 64 exabytes. */ +#define TDB_OFF_UPPER_STEAL 8 +#define TDB_OFF_UPPER_STEAL_EXTRA 7 +/* The bit number where we store extra hash bits. */ +#define TDB_OFF_HASH_EXTRA_BIT 57 +#define TDB_OFF_UPPER_STEAL_SUBHASH_BIT 56 + +/* Additional features we understand. Currently: none. */ +#define TDB_FEATURE_MASK ((uint64_t)0) + +/* The bit number where we store the extra hash bits. */ +/* Convenience mask to get actual offset. */ +#define TDB_OFF_MASK \ + (((1ULL << (64 - TDB_OFF_UPPER_STEAL)) - 1) - TDB_OFF_HASH_GROUP_MASK) + +/* How many buckets in a free list: see size_to_bucket(). */ +#define TDB_FREE_BUCKETS (64 - TDB_OFF_UPPER_STEAL) + +/* We have to be able to fit a free record here. */ +#define TDB_MIN_DATA_LEN \ + (sizeof(struct tdb_free_record) - sizeof(struct tdb_used_record)) + +/* Indicates this entry is not on an flist (can happen during coalescing) */ +#define TDB_FTABLE_NONE ((1ULL << TDB_OFF_UPPER_STEAL) - 1) + +struct tdb_used_record { + /* For on-disk compatibility, we avoid bitfields: + magic: 16, (highest) + key_len_bits: 5, + extra_padding: 32 + hash_bits: 11 + */ + uint64_t magic_and_meta; + /* The bottom key_len_bits*2 are key length, rest is data length. */ + uint64_t key_and_data_len; +}; + +static inline unsigned rec_key_bits(const struct tdb_used_record *r) +{ + return ((r->magic_and_meta >> 43) & ((1 << 5)-1)) * 2; +} + +static inline uint64_t rec_key_length(const struct tdb_used_record *r) +{ + return r->key_and_data_len & ((1ULL << rec_key_bits(r)) - 1); +} + +static inline uint64_t rec_data_length(const struct tdb_used_record *r) +{ + return r->key_and_data_len >> rec_key_bits(r); +} + +static inline uint64_t rec_extra_padding(const struct tdb_used_record *r) +{ + return (r->magic_and_meta >> 11) & 0xFFFFFFFF; +} + +static inline uint32_t rec_hash(const struct tdb_used_record *r) +{ + return r->magic_and_meta & ((1 << 11) - 1); +} + +static inline uint16_t rec_magic(const struct tdb_used_record *r) +{ + return (r->magic_and_meta >> 48); +} + +struct tdb_free_record { + uint64_t magic_and_prev; /* TDB_OFF_UPPER_STEAL bits magic, then prev */ + uint64_t ftable_and_len; /* Len not counting these two fields. */ + /* This is why the minimum record size is 8 bytes. */ + uint64_t next; +}; + +static inline uint64_t frec_prev(const struct tdb_free_record *f) +{ + return f->magic_and_prev & ((1ULL << (64 - TDB_OFF_UPPER_STEAL)) - 1); +} + +static inline uint64_t frec_magic(const struct tdb_free_record *f) +{ + return f->magic_and_prev >> (64 - TDB_OFF_UPPER_STEAL); +} + +static inline uint64_t frec_len(const struct tdb_free_record *f) +{ + return f->ftable_and_len & ((1ULL << (64 - TDB_OFF_UPPER_STEAL))-1); +} + +static inline unsigned frec_ftable(const struct tdb_free_record *f) +{ + return f->ftable_and_len >> (64 - TDB_OFF_UPPER_STEAL); +} + +struct tdb_recovery_record { + uint64_t magic; + /* Length of record (add this header to get total length). */ + uint64_t max_len; + /* Length used. */ + uint64_t len; + /* Old length of file before transaction. */ + uint64_t eof; +}; + +/* If we bottom out of the subhashes, we chain. */ +struct tdb_chain { + tdb_off_t rec[1 << TDB_HASH_GROUP_BITS]; + tdb_off_t next; +}; + +/* this is stored at the front of every database */ +struct tdb_header { + char magic_food[64]; /* for /etc/magic */ + /* FIXME: Make me 32 bit? */ + uint64_t version; /* version of the code */ + uint64_t hash_test; /* result of hashing HASH_MAGIC. */ + uint64_t hash_seed; /* "random" seed written at creation time. */ + tdb_off_t free_table; /* (First) free table. */ + tdb_off_t recovery; /* Transaction recovery area. */ + + uint64_t features_used; /* Features all writers understand */ + uint64_t features_offered; /* Features offered */ + + uint64_t seqnum; /* Sequence number for TDB_SEQNUM */ + + tdb_off_t reserved[23]; + + /* Top level hash table. */ + tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS]; +}; + +struct tdb_freetable { + struct tdb_used_record hdr; + tdb_off_t next; + tdb_off_t buckets[TDB_FREE_BUCKETS]; +}; + +/* Information about a particular (locked) hash entry. */ +struct hash_info { + /* Full hash value of entry. */ + uint64_t h; + /* Start and length of lock acquired. */ + tdb_off_t hlock_start; + tdb_len_t hlock_range; + /* Start of hash group. */ + tdb_off_t group_start; + /* Bucket we belong in. */ + unsigned int home_bucket; + /* Bucket we (or an empty space) were found in. */ + unsigned int found_bucket; + /* How many bits of the hash are already used. */ + unsigned int hash_used; + /* Current working group. */ + tdb_off_t group[1 << TDB_HASH_GROUP_BITS]; +}; + +struct traverse_info { + struct traverse_level { + tdb_off_t hashtable; + /* We ignore groups here, and treat it as a big array. */ + unsigned entry; + unsigned int total_buckets; + } levels[TDB_MAX_LEVELS + 1]; + unsigned int num_levels; + unsigned int toplevel_group; + /* This makes delete-everything-inside-traverse work as expected. */ + tdb_off_t prev; +}; + +enum tdb_lock_flags { + /* WAIT == F_SETLKW, NOWAIT == F_SETLK */ + TDB_LOCK_NOWAIT = 0, + TDB_LOCK_WAIT = 1, + /* If set, don't log an error on failure. */ + TDB_LOCK_PROBE = 2, + /* If set, don't check for recovery (used by recovery code). */ + TDB_LOCK_NOCHECK = 4, +}; + +struct tdb_lock { + struct tdb_context *owner; + uint32_t off; + uint32_t count; + uint32_t ltype; +}; + +/* This is only needed for tdb_access_commit, but used everywhere to + * simplify. */ +struct tdb_access_hdr { + struct tdb_access_hdr *next; + tdb_off_t off; + tdb_len_t len; + bool convert; +}; + +struct tdb_file { + /* Single list of all TDBs, to detect multiple opens. */ + struct tdb_file *next; + + /* How many are sharing us? */ + unsigned int refcnt; + + /* Mmap (if any), or malloc (for TDB_INTERNAL). */ + void *map_ptr; + + /* How much space has been mapped (<= current file size) */ + tdb_len_t map_size; + + /* The file descriptor (-1 for TDB_INTERNAL). */ + int fd; + + /* Lock information */ + pid_t locker; + struct tdb_lock allrecord_lock; + size_t num_lockrecs; + struct tdb_lock *lockrecs; + + /* Identity of this file. */ + dev_t device; + ino_t inode; +}; + +struct tdb_context { + /* Filename of the database. */ + const char *name; + + /* Are we accessing directly? (debugging check). */ + int direct_access; + + /* Operating read-only? (Opened O_RDONLY, or in traverse_read) */ + bool read_only; + + /* mmap read only? */ + int mmap_flags; + + /* the flags passed to tdb_open, for tdb_reopen. */ + uint32_t flags; + + /* Logging function */ + void (*log_fn)(struct tdb_context *tdb, + enum tdb_log_level level, + const char *message, + void *data); + void *log_data; + + /* Hash function. */ + uint64_t (*hash_fn)(const void *key, size_t len, uint64_t seed, void *); + void *hash_data; + uint64_t hash_seed; + + /* low level (fnctl) lock functions. */ + int (*lock_fn)(int fd, int rw, off_t off, off_t len, bool w, void *); + int (*unlock_fn)(int fd, int rw, off_t off, off_t len, void *); + void *lock_data; + + /* Set if we are in a transaction. */ + struct tdb_transaction *transaction; + + /* What free table are we using? */ + tdb_off_t ftable_off; + unsigned int ftable; + + /* IO methods: changes for transactions. */ + const struct tdb_methods *methods; + + /* Our statistics. */ + struct tdb_attribute_stats stats; + + /* Direct access information */ + struct tdb_access_hdr *access; + + /* Last error we returned. */ + enum TDB_ERROR last_error; + + /* The actual file information */ + struct tdb_file *file; +}; + +struct tdb_methods { + enum TDB_ERROR (*tread)(struct tdb_context *, tdb_off_t, void *, + tdb_len_t); + enum TDB_ERROR (*twrite)(struct tdb_context *, tdb_off_t, const void *, + tdb_len_t); + enum TDB_ERROR (*oob)(struct tdb_context *, tdb_off_t, bool); + enum TDB_ERROR (*expand_file)(struct tdb_context *, tdb_len_t); + void *(*direct)(struct tdb_context *, tdb_off_t, size_t, bool); +}; + +/* + internal prototypes +*/ +/* hash.c: */ +tdb_bool_err first_in_hash(struct tdb_context *tdb, + struct traverse_info *tinfo, + TDB_DATA *kbuf, size_t *dlen); + +tdb_bool_err next_in_hash(struct tdb_context *tdb, + struct traverse_info *tinfo, + TDB_DATA *kbuf, size_t *dlen); + +/* Hash random memory. */ +uint64_t tdb_hash(struct tdb_context *tdb, const void *ptr, size_t len); + +/* Hash on disk. */ +uint64_t hash_record(struct tdb_context *tdb, tdb_off_t off); + +/* Find and lock a hash entry (or where it would be). */ +tdb_off_t find_and_lock(struct tdb_context *tdb, + struct tdb_data key, + int ltype, + struct hash_info *h, + struct tdb_used_record *rec, + struct traverse_info *tinfo); + +enum TDB_ERROR replace_in_hash(struct tdb_context *tdb, + struct hash_info *h, + tdb_off_t new_off); + +enum TDB_ERROR add_to_hash(struct tdb_context *tdb, struct hash_info *h, + tdb_off_t new_off); + +enum TDB_ERROR delete_from_hash(struct tdb_context *tdb, struct hash_info *h); + +/* For tdb_check */ +bool is_subhash(tdb_off_t val); + +/* free.c: */ +enum TDB_ERROR tdb_ftable_init(struct tdb_context *tdb); + +/* check.c needs these to iterate through free lists. */ +tdb_off_t first_ftable(struct tdb_context *tdb); +tdb_off_t next_ftable(struct tdb_context *tdb, tdb_off_t ftable); + +/* This returns space or -ve error number. */ +tdb_off_t alloc(struct tdb_context *tdb, size_t keylen, size_t datalen, + uint64_t hash, unsigned magic, bool growing); + +/* Put this record in a free list. */ +enum TDB_ERROR add_free_record(struct tdb_context *tdb, + tdb_off_t off, tdb_len_t len_with_header, + enum tdb_lock_flags waitflag, + bool coalesce_ok); + +/* Set up header for a used/ftable/htable/chain record. */ +enum TDB_ERROR set_header(struct tdb_context *tdb, + struct tdb_used_record *rec, + unsigned magic, uint64_t keylen, uint64_t datalen, + uint64_t actuallen, unsigned hashlow); + +/* Used by tdb_check to verify. */ +unsigned int size_to_bucket(tdb_len_t data_len); +tdb_off_t bucket_off(tdb_off_t ftable_off, unsigned bucket); + +/* Used by tdb_summary */ +tdb_off_t dead_space(struct tdb_context *tdb, tdb_off_t off); + +/* io.c: */ +/* Initialize tdb->methods. */ +void tdb_io_init(struct tdb_context *tdb); + +/* Convert endian of the buffer if required. */ +void *tdb_convert(const struct tdb_context *tdb, void *buf, tdb_len_t size); + +/* Unmap and try to map the tdb. */ +void tdb_munmap(struct tdb_file *file); +void tdb_mmap(struct tdb_context *tdb); + +/* Either alloc a copy, or give direct access. Release frees or noop. */ +const void *tdb_access_read(struct tdb_context *tdb, + tdb_off_t off, tdb_len_t len, bool convert); +void *tdb_access_write(struct tdb_context *tdb, + tdb_off_t off, tdb_len_t len, bool convert); + +/* Release result of tdb_access_read/write. */ +void tdb_access_release(struct tdb_context *tdb, const void *p); +/* Commit result of tdb_acces_write. */ +enum TDB_ERROR tdb_access_commit(struct tdb_context *tdb, void *p); + +/* Convenience routine to get an offset. */ +tdb_off_t tdb_read_off(struct tdb_context *tdb, tdb_off_t off); + +/* Write an offset at an offset. */ +enum TDB_ERROR tdb_write_off(struct tdb_context *tdb, tdb_off_t off, + tdb_off_t val); + +/* Clear an ondisk area. */ +enum TDB_ERROR zero_out(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len); + +/* Return a non-zero offset between >= start < end in this array (or end). */ +tdb_off_t tdb_find_nonzero_off(struct tdb_context *tdb, + tdb_off_t base, + uint64_t start, + uint64_t end); + +/* Return a zero offset in this array, or num. */ +tdb_off_t tdb_find_zero_off(struct tdb_context *tdb, tdb_off_t off, + uint64_t num); + +/* Allocate and make a copy of some offset. */ +void *tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_len_t len); + +/* Writes a converted copy of a record. */ +enum TDB_ERROR tdb_write_convert(struct tdb_context *tdb, tdb_off_t off, + const void *rec, size_t len); + +/* Reads record and converts it */ +enum TDB_ERROR tdb_read_convert(struct tdb_context *tdb, tdb_off_t off, + void *rec, size_t len); + +/* Bump the seqnum (caller checks for tdb->flags & TDB_SEQNUM) */ +void tdb_inc_seqnum(struct tdb_context *tdb); + +/* lock.c: */ +/* Lock/unlock a range of hashes. */ +enum TDB_ERROR tdb_lock_hashes(struct tdb_context *tdb, + tdb_off_t hash_lock, tdb_len_t hash_range, + int ltype, enum tdb_lock_flags waitflag); +enum TDB_ERROR tdb_unlock_hashes(struct tdb_context *tdb, + tdb_off_t hash_lock, + tdb_len_t hash_range, int ltype); + +/* For closing the file. */ +void tdb_lock_cleanup(struct tdb_context *tdb); + +/* Lock/unlock a particular free bucket. */ +enum TDB_ERROR tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off, + enum tdb_lock_flags waitflag); +void tdb_unlock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off); + +/* Serialize transaction start. */ +enum TDB_ERROR tdb_transaction_lock(struct tdb_context *tdb, int ltype); +void tdb_transaction_unlock(struct tdb_context *tdb, int ltype); + +/* Do we have any hash locks (ie. via tdb_chainlock) ? */ +bool tdb_has_hash_locks(struct tdb_context *tdb); + +/* Lock entire database. */ +enum TDB_ERROR tdb_allrecord_lock(struct tdb_context *tdb, int ltype, + enum tdb_lock_flags flags, bool upgradable); +void tdb_allrecord_unlock(struct tdb_context *tdb, int ltype); +enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb); + +/* Serialize db open. */ +enum TDB_ERROR tdb_lock_open(struct tdb_context *tdb, + int ltype, enum tdb_lock_flags flags); +void tdb_unlock_open(struct tdb_context *tdb, int ltype); +bool tdb_has_open_lock(struct tdb_context *tdb); + +/* Serialize db expand. */ +enum TDB_ERROR tdb_lock_expand(struct tdb_context *tdb, int ltype); +void tdb_unlock_expand(struct tdb_context *tdb, int ltype); +bool tdb_has_expansion_lock(struct tdb_context *tdb); + +/* If it needs recovery, grab all the locks and do it. */ +enum TDB_ERROR tdb_lock_and_recover(struct tdb_context *tdb); + +/* Default lock and unlock functions. */ +int tdb_fcntl_lock(int fd, int rw, off_t off, off_t len, bool waitflag, void *); +int tdb_fcntl_unlock(int fd, int rw, off_t off, off_t len, void *); + +/* transaction.c: */ +enum TDB_ERROR tdb_transaction_recover(struct tdb_context *tdb); +tdb_bool_err tdb_needs_recovery(struct tdb_context *tdb); + +/* tdb.c: */ +enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb, + enum TDB_ERROR ecode, + enum tdb_log_level level, + const char *fmt, ...); + +#ifdef TDB_TRACE +void tdb_trace(struct tdb_context *tdb, const char *op); +void tdb_trace_seqnum(struct tdb_context *tdb, uint32_t seqnum, const char *op); +void tdb_trace_open(struct tdb_context *tdb, const char *op, + unsigned hash_size, unsigned tdb_flags, unsigned open_flags); +void tdb_trace_ret(struct tdb_context *tdb, const char *op, int ret); +void tdb_trace_retrec(struct tdb_context *tdb, const char *op, TDB_DATA ret); +void tdb_trace_1rec(struct tdb_context *tdb, const char *op, + TDB_DATA rec); +void tdb_trace_1rec_ret(struct tdb_context *tdb, const char *op, + TDB_DATA rec, int ret); +void tdb_trace_1rec_retrec(struct tdb_context *tdb, const char *op, + TDB_DATA rec, TDB_DATA ret); +void tdb_trace_2rec_flag_ret(struct tdb_context *tdb, const char *op, + TDB_DATA rec1, TDB_DATA rec2, unsigned flag, + int ret); +void tdb_trace_2rec_retrec(struct tdb_context *tdb, const char *op, + TDB_DATA rec1, TDB_DATA rec2, TDB_DATA ret); +#else +#define tdb_trace(tdb, op) +#define tdb_trace_seqnum(tdb, seqnum, op) +#define tdb_trace_open(tdb, op, hash_size, tdb_flags, open_flags) +#define tdb_trace_ret(tdb, op, ret) +#define tdb_trace_retrec(tdb, op, ret) +#define tdb_trace_1rec(tdb, op, rec) +#define tdb_trace_1rec_ret(tdb, op, rec, ret) +#define tdb_trace_1rec_retrec(tdb, op, rec, ret) +#define tdb_trace_2rec_flag_ret(tdb, op, rec1, rec2, flag, ret) +#define tdb_trace_2rec_retrec(tdb, op, rec1, rec2, ret) +#endif /* !TDB_TRACE */ + +#endif |