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author | rgrimes <rgrimes@FreeBSD.org> | 1994-05-27 05:00:24 +0000 |
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committer | rgrimes <rgrimes@FreeBSD.org> | 1994-05-27 05:00:24 +0000 |
commit | be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da (patch) | |
tree | a18a706dffa5baf86a3b12bbfb4f81caa097f349 /lib/libc/db/man | |
parent | 2a27bd86e6002c871e3b5561a5334653bb222a77 (diff) | |
download | FreeBSD-src-be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da.zip FreeBSD-src-be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da.tar.gz |
BSD 4.4 Lite Lib Sources
Diffstat (limited to 'lib/libc/db/man')
-rw-r--r-- | lib/libc/db/man/Makefile.inc | 7 | ||||
-rw-r--r-- | lib/libc/db/man/btree.3 | 226 | ||||
-rw-r--r-- | lib/libc/db/man/dbopen.3 | 476 | ||||
-rw-r--r-- | lib/libc/db/man/hash.3 | 152 | ||||
-rw-r--r-- | lib/libc/db/man/mpool.3 | 219 | ||||
-rw-r--r-- | lib/libc/db/man/recno.3 | 196 |
6 files changed, 1276 insertions, 0 deletions
diff --git a/lib/libc/db/man/Makefile.inc b/lib/libc/db/man/Makefile.inc new file mode 100644 index 0000000..d8d93f9 --- /dev/null +++ b/lib/libc/db/man/Makefile.inc @@ -0,0 +1,7 @@ +# @(#)Makefile.inc 8.1 (Berkeley) 6/4/93 + +.PATH: ${.CURDIR}/db/man + +# mpool.3 +MAN3+= btree.0 dbopen.0 hash.0 recno.0 +MLINKS+= dbopen.3 db.3 diff --git a/lib/libc/db/man/btree.3 b/lib/libc/db/man/btree.3 new file mode 100644 index 0000000..a51e1e5 --- /dev/null +++ b/lib/libc/db/man/btree.3 @@ -0,0 +1,226 @@ +.\" Copyright (c) 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)btree.3 8.3 (Berkeley) 2/21/94 +.\" +.TH BTREE 3 "February 21, 1994" +.\".UC 7 +.SH NAME +btree \- btree database access method +.SH SYNOPSIS +.nf +.ft B +#include <sys/types.h> +#include <db.h> +.ft R +.fi +.SH DESCRIPTION +The routine +.IR dbopen +is the library interface to database files. +One of the supported file formats is btree files. +The general description of the database access methods is in +.IR dbopen (3), +this manual page describes only the btree specific information. +.PP +The btree data structure is a sorted, balanced tree structure storing +associated key/data pairs. +.PP +The btree access method specific data structure provided to +.I dbopen +is defined in the <db.h> include file as follows: +.PP +typedef struct { +.RS +u_long flags; +.br +u_int cachesize; +.br +int maxkeypage; +.br +int minkeypage; +.br +u_int psize; +.br +int (*compare)(const DBT *key1, const DBT *key2); +.br +size_t (*prefix)(const DBT *key1, const DBT *key2); +.br +int lorder; +.RE +} BTREEINFO; +.PP +The elements of this structure are as follows: +.TP +flags +The flag value is specified by +.IR or 'ing +any of the following values: +.RS +.TP +R_DUP +Permit duplicate keys in the tree, i.e. permit insertion if the key to be +inserted already exists in the tree. +The default behavior, as described in +.IR dbopen (3), +is to overwrite a matching key when inserting a new key or to fail if +the R_NOOVERWRITE flag is specified. +The R_DUP flag is overridden by the R_NOOVERWRITE flag, and if the +R_NOOVERWRITE flag is specified, attempts to insert duplicate keys into +the tree will fail. +.IP +If the database contains duplicate keys, the order of retrieval of +key/data pairs is undefined if the +.I get +routine is used, however, +.I seq +routine calls with the R_CURSOR flag set will always return the logical +``first'' of any group of duplicate keys. +.RE +.TP +cachesize +A suggested maximum size (in bytes) of the memory cache. +This value is +.B only +advisory, and the access method will allocate more memory rather than fail. +Since every search examines the root page of the tree, caching the most +recently used pages substantially improves access time. +In addition, physical writes are delayed as long as possible, so a moderate +cache can reduce the number of I/O operations significantly. +Obviously, using a cache increases (but only increases) the likelihood of +corruption or lost data if the system crashes while a tree is being modified. +If +.I cachesize +is 0 (no size is specified) a default cache is used. +.TP +maxkeypage +The maximum number of keys which will be stored on any single page. +Not currently implemented. +.\" The maximum number of keys which will be stored on any single page. +.\" Because of the way the btree data structure works, +.\" .I maxkeypage +.\" must always be greater than or equal to 2. +.\" If +.\" .I maxkeypage +.\" is 0 (no maximum number of keys is specified) the page fill factor is +.\" made as large as possible (which is almost invariably what is wanted). +.TP +minkeypage +The minimum number of keys which will be stored on any single page. +This value is used to determine which keys will be stored on overflow +pages, i.e. if a key or data item is longer than the pagesize divided +by the minkeypage value, it will be stored on overflow pages instead +of in the page itself. +If +.I minkeypage +is 0 (no minimum number of keys is specified) a value of 2 is used. +.TP +psize +Page size is the size (in bytes) of the pages used for nodes in the tree. +The minimum page size is 512 bytes and the maximum page size is 64K. +If +.I psize +is 0 (no page size is specified) a page size is chosen based on the +underlying file system I/O block size. +.TP +compare +Compare is the key comparison function. +It must return an integer less than, equal to, or greater than zero if the +first key argument is considered to be respectively less than, equal to, +or greater than the second key argument. +The same comparison function must be used on a given tree every time it +is opened. +If +.I compare +is NULL (no comparison function is specified), the keys are compared +lexically, with shorter keys considered less than longer keys. +.TP +prefix +Prefix is the prefix comparison function. +If specified, this routine must return the number of bytes of the second key +argument which are necessary to determine that it is greater than the first +key argument. +If the keys are equal, the key length should be returned. +Note, the usefulness of this routine is very data dependent, but, in some +data sets can produce significantly reduced tree sizes and search times. +If +.I prefix +is NULL (no prefix function is specified), +.B and +no comparison function is specified, a default lexical comparison routine +is used. +If +.I prefix +is NULL and a comparison routine is specified, no prefix comparison is +done. +.TP +lorder +The byte order for integers in the stored database metadata. +The number should represent the order as an integer; for example, +big endian order would be the number 4,321. +If +.I lorder +is 0 (no order is specified) the current host order is used. +.PP +If the file already exists (and the O_TRUNC flag is not specified), the +values specified for the parameters flags, lorder and psize are ignored +in favor of the values used when the tree was created. +.PP +Forward sequential scans of a tree are from the least key to the greatest. +.PP +Space freed up by deleting key/data pairs from the tree is never reclaimed, +although it is normally made available for reuse. +This means that the btree storage structure is grow-only. +The only solutions are to avoid excessive deletions, or to create a fresh +tree periodically from a scan of an existing one. +.PP +Searches, insertions, and deletions in a btree will all complete in +O lg base N where base is the average fill factor. +Often, inserting ordered data into btrees results in a low fill factor. +This implementation has been modified to make ordered insertion the best +case, resulting in a much better than normal page fill factor. +.SH "SEE ALSO" +.IR dbopen (3), +.IR hash (3), +.IR mpool (3), +.IR recno (3) +.sp +.IR "The Ubiquitous B-tree" , +Douglas Comer, ACM Comput. Surv. 11, 2 (June 1979), 121-138. +.sp +.IR "Prefix B-trees" , +Bayer and Unterauer, ACM Transactions on Database Systems, Vol. 2, 1 +(March 1977), 11-26. +.sp +.IR "The Art of Computer Programming Vol. 3: Sorting and Searching" , +D.E. Knuth, 1968, pp 471-480. +.SH BUGS +Only big and little endian byte order is supported. diff --git a/lib/libc/db/man/dbopen.3 b/lib/libc/db/man/dbopen.3 new file mode 100644 index 0000000..f06a4ef --- /dev/null +++ b/lib/libc/db/man/dbopen.3 @@ -0,0 +1,476 @@ +.\" Copyright (c) 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)dbopen.3 8.5 (Berkeley) 1/2/94 +.\" +.TH DBOPEN 3 "January 2, 1994" +.UC 7 +.SH NAME +dbopen \- database access methods +.SH SYNOPSIS +.nf +.ft B +#include <sys/types.h> +#include <limits.h> +#include <db.h> + +DB * +dbopen(const char *file, int flags, int mode, DBTYPE type, +.ti +5 +const void *openinfo); +.ft R +.fi +.SH DESCRIPTION +.IR Dbopen +is the library interface to database files. +The supported file formats are btree, hashed and UNIX file oriented. +The btree format is a representation of a sorted, balanced tree structure. +The hashed format is an extensible, dynamic hashing scheme. +The flat-file format is a byte stream file with fixed or variable length +records. +The formats and file format specific information are described in detail +in their respective manual pages +.IR btree (3), +.IR hash (3) +and +.IR recno (3). +.PP +Dbopen opens +.I file +for reading and/or writing. +Files never intended to be preserved on disk may be created by setting +the file parameter to NULL. +.PP +The +.I flags +and +.I mode arguments +are as specified to the +.IR open (2) +routine, however, only the O_CREAT, O_EXCL, O_EXLOCK, O_NONBLOCK, +O_RDONLY, O_RDWR, O_SHLOCK and O_TRUNC flags are meaningful. +(Note, opening a database file O_WRONLY is not possible.) +.\"Three additional options may be specified by +.\".IR or 'ing +.\"them into the +.\".I flags +.\"argument. +.\".TP +.\"DB_LOCK +.\"Do the necessary locking in the database to support concurrent access. +.\"If concurrent access isn't needed or the database is read-only this +.\"flag should not be set, as it tends to have an associated performance +.\"penalty. +.\".TP +.\"DB_SHMEM +.\"Place the underlying memory pool used by the database in shared +.\"memory. +.\"Necessary for concurrent access. +.\".TP +.\"DB_TXN +.\"Support transactions in the database. +.\"The DB_LOCK and DB_SHMEM flags must be set as well. +.PP +The +.I type +argument is of type DBTYPE (as defined in the <db.h> include file) and +may be set to DB_BTREE, DB_HASH or DB_RECNO. +.PP +The +.I openinfo +argument is a pointer to an access method specific structure described +in the access method's manual page. +If +.I openinfo +is NULL, each access method will use defaults appropriate for the system +and the access method. +.PP +.I Dbopen +returns a pointer to a DB structure on success and NULL on error. +The DB structure is defined in the <db.h> include file, and contains at +least the following fields: +.sp +.nf +typedef struct { +.RS +DBTYPE type; +int (*close)(const DB *db); +int (*del)(const DB *db, const DBT *key, u_int flags); +int (*fd)(const DB *db); +int (*get)(const DB *db, DBT *key, DBT *data, u_int flags); +int (*put)(const DB *db, DBT *key, const DBT *data, +.ti +5 +u_int flags); +int (*sync)(const DB *db, u_int flags); +int (*seq)(const DB *db, DBT *key, DBT *data, u_int flags); +.RE +} DB; +.fi +.PP +These elements describe a database type and a set of functions performing +various actions. +These functions take a pointer to a structure as returned by +.IR dbopen , +and sometimes one or more pointers to key/data structures and a flag value. +.TP +type +The type of the underlying access method (and file format). +.TP +close +A pointer to a routine to flush any cached information to disk, free any +allocated resources, and close the underlying file(s). +Since key/data pairs may be cached in memory, failing to sync the file +with a +.I close +or +.I sync +function may result in inconsistent or lost information. +.I Close +routines return -1 on error (setting +.IR errno ) +and 0 on success. +.TP +del +A pointer to a routine to remove key/data pairs from the database. +.IP +The parameter +.I flag +may be set to the following value: +.RS +.TP +R_CURSOR +Delete the record referenced by the cursor. +The cursor must have previously been initialized. +.RE +.IP +.I Delete +routines return -1 on error (setting +.IR errno ), +0 on success, and 1 if the specified +.I key +was not in the file. +.TP +fd +A pointer to a routine which returns a file descriptor representative +of the underlying database. +A file descriptor referencing the same file will be returned to all +processes which call +.I dbopen +with the same +.I file +name. +This file descriptor may be safely used as an argument to the +.IR fcntl (2) +and +.IR flock (2) +locking functions. +The file descriptor is not necessarily associated with any of the +underlying files used by the access method. +No file descriptor is available for in memory databases. +.I Fd +routines return -1 on error (setting +.IR errno ), +and the file descriptor on success. +.TP +get +A pointer to a routine which is the interface for keyed retrieval from +the database. +The address and length of the data associated with the specified +.I key +are returned in the structure referenced by +.IR data . +.I Get +routines return -1 on error (setting +.IR errno ), +0 on success, and 1 if the +.I key +was not in the file. +.TP +put +A pointer to a routine to store key/data pairs in the database. +.IP +The parameter +.I flag +may be set to one of the following values: +.RS +.TP +R_CURSOR +Replace the key/data pair referenced by the cursor. +The cursor must have previously been initialized. +.TP +R_IAFTER +Append the data immediately after the data referenced by +.IR key , +creating a new key/data pair. +The record number of the appended key/data pair is returned in the +.I key +structure. +(Applicable only to the DB_RECNO access method.) +.TP +R_IBEFORE +Insert the data immediately before the data referenced by +.IR key , +creating a new key/data pair. +The record number of the inserted key/data pair is returned in the +.I key +structure. +(Applicable only to the DB_RECNO access method.) +.TP +R_NOOVERWRITE +Enter the new key/data pair only if the key does not previously exist. +.TP +R_SETCURSOR +Store the key/data pair, setting or initializing the position of the +cursor to reference it. +(Applicable only to the DB_BTREE and DB_RECNO access methods.) +.RE +.IP +R_SETCURSOR is available only for the DB_BTREE and DB_RECNO access +methods because it implies that the keys have an inherent order +which does not change. +.IP +R_IAFTER and R_IBEFORE are available only for the DB_RECNO +access method because they each imply that the access method is able to +create new keys. +This is only true if the keys are ordered and independent, record numbers +for example. +.IP +The default behavior of the +.I put +routines is to enter the new key/data pair, replacing any previously +existing key. +.IP +.I Put +routines return -1 on error (setting +.IR errno ), +0 on success, and 1 if the R_NOOVERWRITE +.I flag +was set and the key already exists in the file. +.TP +seq +A pointer to a routine which is the interface for sequential +retrieval from the database. +The address and length of the key are returned in the structure +referenced by +.IR key , +and the address and length of the data are returned in the +structure referenced +by +.IR data . +.IP +Sequential key/data pair retrieval may begin at any time, and the +position of the ``cursor'' is not affected by calls to the +.IR del , +.IR get , +.IR put , +or +.I sync +routines. +Modifications to the database during a sequential scan will be reflected +in the scan, i.e. records inserted behind the cursor will not be returned +while records inserted in front of the cursor will be returned. +.IP +The flag value +.B must +be set to one of the following values: +.RS +.TP +R_CURSOR +The data associated with the specified key is returned. +This differs from the +.I get +routines in that it sets or initializes the cursor to the location of +the key as well. +(Note, for the DB_BTREE access method, the returned key is not necessarily an +exact match for the specified key. +The returned key is the smallest key greater than or equal to the specified +key, permitting partial key matches and range searches.) +.TP +R_FIRST +The first key/data pair of the database is returned, and the cursor +is set or initialized to reference it. +.TP +R_LAST +The last key/data pair of the database is returned, and the cursor +is set or initialized to reference it. +(Applicable only to the DB_BTREE and DB_RECNO access methods.) +.TP +R_NEXT +Retrieve the key/data pair immediately after the cursor. +If the cursor is not yet set, this is the same as the R_FIRST flag. +.TP +R_PREV +Retrieve the key/data pair immediately before the cursor. +If the cursor is not yet set, this is the same as the R_LAST flag. +(Applicable only to the DB_BTREE and DB_RECNO access methods.) +.RE +.IP +R_LAST and R_PREV are available only for the DB_BTREE and DB_RECNO +access methods because they each imply that the keys have an inherent +order which does not change. +.IP +.I Seq +routines return -1 on error (setting +.IR errno ), +0 on success and 1 if there are no key/data pairs less than or greater +than the specified or current key. +If the DB_RECNO access method is being used, and if the database file +is a character special file and no complete key/data pairs are currently +available, the +.I seq +routines return 2. +.TP +sync +A pointer to a routine to flush any cached information to disk. +If the database is in memory only, the +.I sync +routine has no effect and will always succeed. +.IP +The flag value may be set to the following value: +.RS +.TP +R_RECNOSYNC +If the DB_RECNO access method is being used, this flag causes +the sync routine to apply to the btree file which underlies the +recno file, not the recno file itself. +(See the +.I bfname +field of the +.IR recno (3) +manual page for more information.) +.RE +.IP +.I Sync +routines return -1 on error (setting +.IR errno ) +and 0 on success. +.SH "KEY/DATA PAIRS" +Access to all file types is based on key/data pairs. +Both keys and data are represented by the following data structure: +.PP +typedef struct { +.RS +void *data; +.br +size_t size; +.RE +} DBT; +.PP +The elements of the DBT structure are defined as follows: +.TP +data +A pointer to a byte string. +.TP +size +The length of the byte string. +.PP +Key and data byte strings may reference strings of essentially unlimited +length although any two of them must fit into available memory at the same +time. +It should be noted that the access methods provide no guarantees about +byte string alignment. +.SH ERRORS +The +.I dbopen +routine may fail and set +.I errno +for any of the errors specified for the library routines +.IR open (2) +and +.IR malloc (3) +or the following: +.TP +[EFTYPE] +A file is incorrectly formatted. +.TP +[EINVAL] +A parameter has been specified (hash function, pad byte etc.) that is +incompatible with the current file specification or which is not +meaningful for the function (for example, use of the cursor without +prior initialization) or there is a mismatch between the version +number of file and the software. +.PP +The +.I close +routines may fail and set +.I errno +for any of the errors specified for the library routines +.IR close (2), +.IR read (2), +.IR write (2), +.IR free (3), +or +.IR fsync (2). +.PP +The +.IR del , +.IR get , +.I put +and +.I seq +routines may fail and set +.I errno +for any of the errors specified for the library routines +.IR read (2), +.IR write (2), +.IR free (3) +or +.IR malloc (3). +.PP +The +.I fd +routines will fail and set +.I errno +to ENOENT for in memory databases. +.PP +The +.I sync +routines may fail and set +.I errno +for any of the errors specified for the library routine +.IR fsync (2). +.SH "SEE ALSO" +.IR btree (3), +.IR hash (3), +.IR mpool (3), +.IR recno (3) +.sp +.IR "LIBTP: Portable, Modular Transactions for UNIX" , +Margo Seltzer, Michael Olson, USENIX proceedings, Winter 1992. +.SH BUGS +The typedef DBT is a mnemonic for ``data base thang'', and was used +because noone could think of a reasonable name that wasn't already used. +.PP +The file descriptor interface is a kluge and will be deleted in a +future version of the interface. +.PP +None of the access methods provide any form of concurrent access, +locking, or transactions. diff --git a/lib/libc/db/man/hash.3 b/lib/libc/db/man/hash.3 new file mode 100644 index 0000000..3ae00a2 --- /dev/null +++ b/lib/libc/db/man/hash.3 @@ -0,0 +1,152 @@ +.\" Copyright (c) 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)hash.3 8.5 (Berkeley) 2/21/94 +.\" +.TH HASH 3 "February 21, 1994" +.UC 7 +.SH NAME +hash \- hash database access method +.SH SYNOPSIS +.nf +.ft B +#include <sys/types.h> +#include <db.h> +.ft R +.fi +.SH DESCRIPTION +The routine +.IR dbopen +is the library interface to database files. +One of the supported file formats is hash files. +The general description of the database access methods is in +.IR dbopen (3), +this manual page describes only the hash specific information. +.PP +The hash data structure is an extensible, dynamic hashing scheme. +.PP +The access method specific data structure provided to +.I dbopen +is defined in the <db.h> include file as follows: +.sp +typedef struct { +.RS +u_int bsize; +.br +u_int ffactor; +.br +u_int nelem; +.br +u_int cachesize; +.br +u_int32_t (*hash)(const void *, size_t); +.br +int lorder; +.RE +} HASHINFO; +.PP +The elements of this structure are as follows: +.TP +bsize +.I Bsize +defines the hash table bucket size, and is, by default, 256 bytes. +It may be preferable to increase the page size for disk-resident tables +and tables with large data items. +.TP +ffactor +.I Ffactor +indicates a desired density within the hash table. +It is an approximation of the number of keys allowed to accumulate in any +one bucket, determining when the hash table grows or shrinks. +The default value is 8. +.TP +nelem +.I Nelem +is an estimate of the final size of the hash table. +If not set or set too low, hash tables will expand gracefully as keys +are entered, although a slight performance degradation may be noticed. +The default value is 1. +.TP +cachesize +A suggested maximum size, in bytes, of the memory cache. +This value is +.B only +advisory, and the access method will allocate more memory rather +than fail. +.TP +hash +.I Hash +is a user defined hash function. +Since no hash function performs equally well on all possible data, the +user may find that the built-in hash function does poorly on a particular +data set. +User specified hash functions must take two arguments (a pointer to a byte +string and a length) and return a 32-bit quantity to be used as the hash +value. +.TP +lorder +The byte order for integers in the stored database metadata. +The number should represent the order as an integer; for example, +big endian order would be the number 4,321. +If +.I lorder +is 0 (no order is specified) the current host order is used. +If the file already exists, the specified value is ignored and the +value specified when the tree was created is used. +.PP +If the file already exists (and the O_TRUNC flag is not specified), the +values specified for the parameters bsize, ffactor, lorder and nelem are +ignored and the values specified when the tree was created are used. +.PP +If a hash function is specified, +.I hash_open +will attempt to determine if the hash function specified is the same as +the one with which the database was created, and will fail if it is not. +.PP +Backward compatible interfaces to the routines described in +.IR dbm (3), +and +.IR ndbm (3) +are provided, however these interfaces are not compatible with +previous file formats. +.SH "SEE ALSO" +.IR btree (3), +.IR dbopen (3), +.IR mpool (3), +.IR recno (3) +.sp +.IR "Dynamic Hash Tables" , +Per-Ake Larson, Communications of the ACM, April 1988. +.sp +.IR "A New Hash Package for UNIX" , +Margo Seltzer, USENIX Proceedings, Winter 1991. +.SH BUGS +Only big and little endian byte order is supported. diff --git a/lib/libc/db/man/mpool.3 b/lib/libc/db/man/mpool.3 new file mode 100644 index 0000000..c17606e --- /dev/null +++ b/lib/libc/db/man/mpool.3 @@ -0,0 +1,219 @@ +.\" Copyright (c) 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)mpool.3 8.1 (Berkeley) 6/4/93 +.\" +.TH MPOOL 3 "June 4, 1993" +.UC 7 +.SH NAME +mpool \- shared memory buffer pool +.SH SYNOPSIS +.nf +.ft B +#include <db.h> +#include <mpool.h> + +MPOOL * +mpool_open (DBT *key, int fd, pgno_t pagesize, pgno_t maxcache); + +void +mpool_filter (MPOOL *mp, void (*pgin)(void *, pgno_t, void *), +.ti +5 +void (*pgout)(void *, pgno_t, void *), void *pgcookie); + +void * +mpool_new (MPOOL *mp, pgno_t *pgnoaddr); + +void * +mpool_get (MPOOL *mp, pgno_t pgno, u_int flags); + +int +mpool_put (MPOOL *mp, void *pgaddr, u_int flags); + +int +mpool_sync (MPOOL *mp); + +int +mpool_close (MPOOL *mp); +.ft R +.fi +.SH DESCRIPTION +.IR Mpool +is the library interface intended to provide page oriented buffer management +of files. +The buffers may be shared between processes. +.PP +The function +.I mpool_open +initializes a memory pool. +The +.I key +argument is the byte string used to negotiate between multiple +processes wishing to share buffers. +If the file buffers are mapped in shared memory, all processes using +the same key will share the buffers. +If +.I key +is NULL, the buffers are mapped into private memory. +The +.I fd +argument is a file descriptor for the underlying file, which must be seekable. +If +.I key +is non-NULL and matches a file already being mapped, the +.I fd +argument is ignored. +.PP +The +.I pagesize +argument is the size, in bytes, of the pages into which the file is broken up. +The +.I maxcache +argument is the maximum number of pages from the underlying file to cache +at any one time. +This value is not relative to the number of processes which share a file's +buffers, but will be the largest value specified by any of the processes +sharing the file. +.PP +The +.I mpool_filter +function is intended to make transparent input and output processing of the +pages possible. +If the +.I pgin +function is specified, it is called each time a buffer is read into the memory +pool from the backing file. +If the +.I pgout +function is specified, it is called each time a buffer is written into the +backing file. +Both functions are are called with the +.I pgcookie +pointer, the page number and a pointer to the page to being read or written. +.PP +The function +.I mpool_new +takes an MPOOL pointer and an address as arguments. +If a new page can be allocated, a pointer to the page is returned and +the page number is stored into the +.I pgnoaddr +address. +Otherwise, NULL is returned and errno is set. +.PP +The function +.I mpool_get +takes a MPOOL pointer and a page number as arguments. +If the page exists, a pointer to the page is returned. +Otherwise, NULL is returned and errno is set. +The flags parameter is not currently used. +.PP +The function +.I mpool_put +unpins the page referenced by +.IR pgaddr . +.I Pgaddr +must be an address previously returned by +.I mpool_get +or +.IR mpool_new . +The flag value is specified by +.IR or 'ing +any of the following values: +.TP +MPOOL_DIRTY +The page has been modified and needs to be written to the backing file. +.PP +.I Mpool_put +returns 0 on success and -1 if an error occurs. +.PP +The function +.I mpool_sync +writes all modified pages associated with the MPOOL pointer to the +backing file. +.I Mpool_sync +returns 0 on success and -1 if an error occurs. +.PP +The +.I mpool_close +function free's up any allocated memory associated with the memory pool +cookie. +Modified pages are +.B not +written to the backing file. +.I Mpool_close +returns 0 on success and -1 if an error occurs. +.SH ERRORS +The +.I mpool_open +function may fail and set +.I errno +for any of the errors specified for the library routine +.IR malloc (3). +.PP +The +.I mpool_get +function may fail and set +.I errno +for the following: +.TP 15 +[EINVAL] +The requested record doesn't exist. +.PP +The +.I mpool_new +and +.I mpool_get +functions may fail and set +.I errno +for any of the errors specified for the library routines +.IR read (2) , +.IR write (2) , +and +.IR malloc (3). +.PP +The +.I mpool_sync +function may fail and set +.I errno +for any of the errors specified for the library routine +.IR write (2). +.PP +The +.I mpool_close +function may fail and set +.I errno +for any of the errors specified for the library routine +.IR free (3). +.SH "SEE ALSO" +.IR dbopen (3), +.IR btree (3), +.IR hash (3), +.IR recno (3) diff --git a/lib/libc/db/man/recno.3 b/lib/libc/db/man/recno.3 new file mode 100644 index 0000000..a40e6c9 --- /dev/null +++ b/lib/libc/db/man/recno.3 @@ -0,0 +1,196 @@ +.\" Copyright (c) 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)recno.3 8.3 (Berkeley) 2/21/94 +.\" +.TH RECNO 3 "February 21, 1994" +.UC 7 +.SH NAME +recno \- record number database access method +.SH SYNOPSIS +.nf +.ft B +#include <sys/types.h> +#include <db.h> +.ft R +.fi +.SH DESCRIPTION +The routine +.IR dbopen +is the library interface to database files. +One of the supported file formats is record number files. +The general description of the database access methods is in +.IR dbopen (3), +this manual page describes only the recno specific information. +.PP +The record number data structure is either variable or fixed-length +records stored in a flat-file format, accessed by the logical record +number. +The existence of record number five implies the existence of records +one through four, and the deletion of record number one causes +record number five to be renumbered to record number four, as well +as the cursor, if positioned after record number one, to shift down +one record. +.PP +The recno access method specific data structure provided to +.I dbopen +is defined in the <db.h> include file as follows: +.PP +typedef struct { +.RS +u_long flags; +.br +u_int cachesize; +.br +u_int psize; +.br +int lorder; +.br +size_t reclen; +.br +u_char bval; +.br +char *bfname; +.RE +} RECNOINFO; +.PP +The elements of this structure are defined as follows: +.TP +flags +The flag value is specified by +.IR or 'ing +any of the following values: +.RS +.TP +R_FIXEDLEN +The records are fixed-length, not byte delimited. +The structure element +.I reclen +specifies the length of the record, and the structure element +.I bval +is used as the pad character. +.TP +R_NOKEY +In the interface specified by +.IR dbopen , +the sequential record retrieval fills in both the caller's key and +data structures. +If the R_NOKEY flag is specified, the +.I cursor +routines are not required to fill in the key structure. +This permits applications to retrieve records at the end of files without +reading all of the intervening records. +.TP +R_SNAPSHOT +This flag requires that a snapshot of the file be taken when +.I dbopen +is called, instead of permitting any unmodified records to be read from +the original file. +.RE +.TP +cachesize +A suggested maximum size, in bytes, of the memory cache. +This value is +.B only +advisory, and the access method will allocate more memory rather than fail. +If +.I cachesize +is 0 (no size is specified) a default cache is used. +.TP +psize +The recno access method stores the in-memory copies of its records +in a btree. +This value is the size (in bytes) of the pages used for nodes in that tree. +If +.I psize +is 0 (no page size is specified) a page size is chosen based on the +underlying file system I/O block size. +See +.IR btree (3) +for more information. +.TP +lorder +The byte order for integers in the stored database metadata. +The number should represent the order as an integer; for example, +big endian order would be the number 4,321. +If +.I lorder +is 0 (no order is specified) the current host order is used. +.TP +reclen +The length of a fixed-length record. +.TP +bval +The delimiting byte to be used to mark the end of a record for +variable-length records, and the pad character for fixed-length +records. +If no value is specified, newlines (``\en'') are used to mark the end +of variable-length records and fixed-length records are padded with +spaces. +.TP +bfname +The recno access method stores the in-memory copies of its records +in a btree. +If bfname is non-NULL, it specifies the name of the btree file, +as if specified as the file name for a dbopen of a btree file. +.PP +The data part of the key/data pair used by the recno access method +is the same as other access methods. +The key is different. +The +.I data +field of the key should be a pointer to a memory location of type +.IR recno_t , +as defined in the <db.h> include file. +This type is normally the largest unsigned integral type available to +the implementation. +The +.I size +field of the key should be the size of that type. +.PP +In the interface specified by +.IR dbopen , +using the +.I put +interface to create a new record will cause the creation of multiple, +empty records if the record number is more than one greater than the +largest record currently in the database. +.SH "SEE ALSO" +.IR dbopen (3), +.IR hash (3), +.IR mpool (3), +.IR recno (3) +.sp +.IR "Document Processing in a Relational Database System" , +Michael Stonebraker, Heidi Stettner, Joseph Kalash, Antonin Guttman, +Nadene Lynn, Memorandum No. UCB/ERL M82/32, May 1982. +.SH BUGS +Only big and little endian byte order is supported. |