pjs/db/mork/src/orkinStore.h

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
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* the provisions above, a recipient may use your version of this file under
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*
* ***** END LICENSE BLOCK ***** */
#ifndef _ORKINSTORE_
#define _ORKINSTORE_ 1
#ifndef _MDB_
#include "mdb.h"
#endif
#ifndef _MORK_
#include "mork.h"
#endif
#ifndef _MORKNODE_
#include "morkNode.h"
#endif
#ifndef _MORKHANDLE_
#include "morkHandle.h"
#endif
#ifndef _MORKStore_
#include "morkStore.h"
#endif
//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789
#define morkMagic_kStore 0x53746F72 /* ascii 'Stor' */
/*| orkinStore:
|*/
class orkinStore : public morkHandle, public nsIMdbStore { // nsIMdbPort
// { ===== begin morkNode interface =====
public: // morkNode virtual methods
// virtual void CloseMorkNode(morkEnv* ev); // morkHandle is fine
virtual ~orkinStore(); // morkHandle destructor does everything
protected: // construction is protected (use the static Make() method)
orkinStore(morkEnv* ev, // note morkUsage is always morkUsage_kPool
morkHandleFace* ioFace, // must not be nil, cookie for this handle
morkStore* ioObject); // must not be nil, the object for this handle
// void CloseHandle(morkEnv* ev); // don't need to specialize closing
private: // copying is not allowed
orkinStore(const morkHandle& other);
orkinStore& operator=(const morkHandle& other);
// public: // dynamic type identification
// mork_bool IsHandle() const //
// { return IsNode() && mNode_Derived == morkDerived_kHandle; }
// } ===== end morkNode methods =====
protected: // morkHandle memory management operators
void* operator new(size_t inSize, morkPool& ioPool, morkZone& ioZone, morkEnv* ev) CPP_THROW_NEW
{ return ioPool.NewHandle(ev, inSize, &ioZone); }
void* operator new(size_t inSize, morkPool& ioPool, morkEnv* ev) CPP_THROW_NEW
{ return ioPool.NewHandle(ev, inSize, (morkZone*) 0); }
void* operator new(size_t inSize, morkHandleFace* ioFace) CPP_THROW_NEW
{ MORK_USED_1(inSize); return ioFace; }
public: // construction:
static orkinStore* MakeStore(morkEnv* ev, morkStore* ioObject);
public: // utilities:
morkEnv* CanUseStore(nsIMdbEnv* mev, mork_bool inMutable,
mdb_err* outErr) const;
public: // type identification
mork_bool IsOrkinStore() const
{ return mHandle_Magic == morkMagic_kStore; }
mork_bool IsOrkinStoreHandle() const
{ return this->IsHandle() && this->IsOrkinStore(); }
NS_DECL_ISUPPORTS
// { ===== begin nsIMdbObject methods =====
// { ----- begin attribute methods -----
NS_IMETHOD IsFrozenMdbObject(nsIMdbEnv* ev, mdb_bool* outIsReadonly);
// same as nsIMdbPort::GetIsPortReadonly() when this object is inside a port.
// } ----- end attribute methods -----
// { ----- begin factory methods -----
NS_IMETHOD GetMdbFactory(nsIMdbEnv* ev, nsIMdbFactory** acqFactory);
// } ----- end factory methods -----
// { ----- begin ref counting for well-behaved cyclic graphs -----
NS_IMETHOD GetWeakRefCount(nsIMdbEnv* ev, // weak refs
mdb_count* outCount);
NS_IMETHOD GetStrongRefCount(nsIMdbEnv* ev, // strong refs
mdb_count* outCount);
NS_IMETHOD AddWeakRef(nsIMdbEnv* ev);
NS_IMETHOD AddStrongRef(nsIMdbEnv* ev);
NS_IMETHOD CutWeakRef(nsIMdbEnv* ev);
NS_IMETHOD CutStrongRef(nsIMdbEnv* ev);
NS_IMETHOD CloseMdbObject(nsIMdbEnv* ev); // called at strong refs zero
NS_IMETHOD IsOpenMdbObject(nsIMdbEnv* ev, mdb_bool* outOpen);
// } ----- end ref counting -----
// } ===== end nsIMdbObject methods =====
// { ===== begin nsIMdbPort methods =====
// { ----- begin attribute methods -----
NS_IMETHOD GetIsPortReadonly(nsIMdbEnv* ev, mdb_bool* outBool);
NS_IMETHOD GetIsStore(nsIMdbEnv* ev, mdb_bool* outBool);
NS_IMETHOD GetIsStoreAndDirty(nsIMdbEnv* ev, mdb_bool* outBool);
NS_IMETHOD GetUsagePolicy(nsIMdbEnv* ev,
mdbUsagePolicy* ioUsagePolicy);
NS_IMETHOD SetUsagePolicy(nsIMdbEnv* ev,
const mdbUsagePolicy* inUsagePolicy);
// } ----- end attribute methods -----
// { ----- begin memory policy methods -----
NS_IMETHOD IdleMemoryPurge( // do memory management already scheduled
nsIMdbEnv* ev, // context
mdb_size* outEstimatedBytesFreed); // approximate bytes actually freed
NS_IMETHOD SessionMemoryPurge( // request specific footprint decrease
nsIMdbEnv* ev, // context
mdb_size inDesiredBytesFreed, // approximate number of bytes wanted
mdb_size* outEstimatedBytesFreed); // approximate bytes actually freed
NS_IMETHOD PanicMemoryPurge( // desperately free all possible memory
nsIMdbEnv* ev, // context
mdb_size* outEstimatedBytesFreed); // approximate bytes actually freed
// } ----- end memory policy methods -----
// { ----- begin filepath methods -----
NS_IMETHOD GetPortFilePath(
nsIMdbEnv* ev, // context
mdbYarn* outFilePath, // name of file holding port content
mdbYarn* outFormatVersion); // file format description
NS_IMETHOD GetPortFile(
nsIMdbEnv* ev, // context
nsIMdbFile** acqFile); // acquire file used by port or store
// } ----- end filepath methods -----
// { ----- begin export methods -----
NS_IMETHOD BestExportFormat( // determine preferred export format
nsIMdbEnv* ev, // context
mdbYarn* outFormatVersion); // file format description
NS_IMETHOD
CanExportToFormat( // can export content in given specific format?
nsIMdbEnv* ev, // context
const char* inFormatVersion, // file format description
mdb_bool* outCanExport); // whether ExportSource() might succeed
NS_IMETHOD ExportToFormat( // export content in given specific format
nsIMdbEnv* ev, // context
// const char* inFilePath, // the file to receive exported content
nsIMdbFile* ioFile, // destination abstract file interface
const char* inFormatVersion, // file format description
nsIMdbThumb** acqThumb); // acquire thumb for incremental export
// Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
// then the export will be finished.
// } ----- end export methods -----
// { ----- begin token methods -----
NS_IMETHOD TokenToString( // return a string name for an integer token
nsIMdbEnv* ev, // context
mdb_token inToken, // token for inTokenName inside this port
mdbYarn* outTokenName); // the type of table to access
NS_IMETHOD StringToToken( // return an integer token for scope name
nsIMdbEnv* ev, // context
const char* inTokenName, // Latin1 string to tokenize if possible
mdb_token* outToken); // token for inTokenName inside this port
// String token zero is never used and never supported. If the port
// is a mutable store, then StringToToken() to create a new
// association of inTokenName with a new integer token if possible.
// But a readonly port will return zero for an unknown scope name.
NS_IMETHOD QueryToken( // like StringToToken(), but without adding
nsIMdbEnv* ev, // context
const char* inTokenName, // Latin1 string to tokenize if possible
mdb_token* outToken); // token for inTokenName inside this port
// QueryToken() will return a string token if one already exists,
// but unlike StringToToken(), will not assign a new token if not
// already in use.
// } ----- end token methods -----
// { ----- begin row methods -----
NS_IMETHOD HasRow( // contains a row with the specified oid?
nsIMdbEnv* ev, // context
const mdbOid* inOid, // hypothetical row oid
mdb_bool* outHasRow); // whether GetRow() might succeed
NS_IMETHOD GetRowRefCount( // get number of tables that contain a row
nsIMdbEnv* ev, // context
const mdbOid* inOid, // hypothetical row oid
mdb_count* outRefCount); // number of tables containing inRowKey
NS_IMETHOD GetRow( // access one row with specific oid
nsIMdbEnv* ev, // context
const mdbOid* inOid, // hypothetical row oid
nsIMdbRow** acqRow); // acquire specific row (or null)
NS_IMETHOD FindRow(nsIMdbEnv* ev, // search for row with matching cell
mdb_scope inRowScope, // row scope for row ids
mdb_column inColumn, // the column to search (and maintain an index)
const mdbYarn* inTargetCellValue, // cell value for which to search
mdbOid* outRowOid, // out row oid on match (or {0,-1} for no match)
nsIMdbRow** acqRow); // acquire matching row (or nil for no match)
// FindRow() searches for one row that has a cell in column inColumn with
// a contained value with the same form (i.e. charset) and is byte-wise
// identical to the blob described by yarn inTargetCellValue. Both content
// and form of the yarn must be an exact match to find a matching row.
//
// (In other words, both a yarn's blob bytes and form are significant. The
// form is not expected to vary in columns used for identity anyway. This
// is intended to make the cost of FindRow() cheaper for MDB implementors,
// since any cell value atomization performed internally must necessarily
// make yarn form significant in order to avoid data loss in atomization.)
//
// FindRow() can lazily create an index on attribute inColumn for all rows
// with that attribute in row space scope inRowScope, so that subsequent
// calls to FindRow() will perform faster. Such an index might or might
// not be persistent (but this seems desirable if it is cheap to do so).
// Note that lazy index creation in readonly DBs is not very feasible.
//
// This FindRow() interface assumes that attribute inColumn is effectively
// an alternative means of unique identification for a row in a rowspace,
// so correct behavior is only guaranteed when no duplicates for this col
// appear in the given set of rows. (If more than one row has the same cell
// value in this column, no more than one will be found; and cutting one of
// two duplicate rows can cause the index to assume no other such row lives
// in the row space, so future calls return nil for negative search results
// even though some duplicate row might still live within the rowspace.)
//
// In other words, the FindRow() implementation is allowed to assume simple
// hash tables mapping unqiue column keys to associated row values will be
// sufficient, where any duplication is not recorded because only one copy
// of a given key need be remembered. Implementors are not required to sort
// all rows by the specified column.
// } ----- end row methods -----
// { ----- begin table methods -----
NS_IMETHOD HasTable( // supports a table with the specified oid?
nsIMdbEnv* ev, // context
const mdbOid* inOid, // hypothetical table oid
mdb_bool* outHasTable); // whether GetTable() might succeed
NS_IMETHOD GetTable( // access one table with specific oid
nsIMdbEnv* ev, // context
const mdbOid* inOid, // hypothetical table oid
nsIMdbTable** acqTable); // acquire specific table (or null)
NS_IMETHOD HasTableKind( // supports a table of the specified type?
nsIMdbEnv* ev, // context
mdb_scope inRowScope, // rid scope for row ids
mdb_kind inTableKind, // the type of table to access
mdb_count* outTableCount, // current number of such tables
mdb_bool* outSupportsTable); // whether GetTableKind() might succeed
NS_IMETHOD GetTableKind( // access one (random) table of specific type
nsIMdbEnv* ev, // context
mdb_scope inRowScope, // row scope for row ids
mdb_kind inTableKind, // the type of table to access
mdb_count* outTableCount, // current number of such tables
mdb_bool* outMustBeUnique, // whether port can hold only one of these
nsIMdbTable** acqTable); // acquire scoped collection of rows
NS_IMETHOD
GetPortTableCursor( // get cursor for all tables of specific type
nsIMdbEnv* ev, // context
mdb_scope inRowScope, // row scope for row ids
mdb_kind inTableKind, // the type of table to access
nsIMdbPortTableCursor** acqCursor); // all such tables in the port
// } ----- end table methods -----
// { ----- begin commit methods -----
NS_IMETHOD ShouldCompress( // store wastes at least inPercentWaste?
nsIMdbEnv* ev, // context
mdb_percent inPercentWaste, // 0..100 percent file size waste threshold
mdb_percent* outActualWaste, // 0..100 percent of file actually wasted
mdb_bool* outShould); // true when about inPercentWaste% is wasted
// ShouldCompress() returns true if the store can determine that the file
// will shrink by an estimated percentage of inPercentWaste% (or more) if
// CompressCommit() is called, because that percentage of the file seems
// to be recoverable free space. The granularity is only in terms of
// percentage points, and any value over 100 is considered equal to 100.
//
// If a store only has an approximate idea how much space might be saved
// during a compress, then a best guess should be made. For example, the
// Mork implementation might keep track of how much file space began with
// text content before the first updating transaction, and then consider
// all content following the start of the first transaction as potentially
// wasted space if it is all updates and not just new content. (This is
// a safe assumption in the sense that behavior will stabilize on a low
// estimate of wastage after a commit removes all transaction updates.)
//
// Some db formats might attempt to keep a very accurate reckoning of free
// space size, so a very accurate determination can be made. But other db
// formats might have difficulty determining size of free space, and might
// require some lengthy calculation to answer. This is the reason for
// passing in the percentage threshold of interest, so that such lengthy
// computations can terminate early as soon as at least inPercentWaste is
// found, so that the entire file need not be groveled when unnecessary.
// However, we hope implementations will always favor fast but imprecise
// heuristic answers instead of extremely slow but very precise answers.
//
// If the outActualWaste parameter is non-nil, it will be used to return
// the actual estimated space wasted as a percentage of file size. (This
// parameter is provided so callers need not call repeatedly with altered
// inPercentWaste values to isolate the actual wastage figure.) Note the
// actual wastage figure returned can exactly equal inPercentWaste even
// when this grossly underestimates the real figure involved, if the db
// finds it very expensive to determine the extent of wastage after it is
// known to at least exceed inPercentWaste. Note we expect that whenever
// outShould returns true, that outActualWaste returns >= inPercentWaste.
//
// The effect of different inPercentWaste values is not very uniform over
// the permitted range. For example, 50 represents 50% wastage, or a file
// that is about double what it should be ideally. But 99 represents 99%
// wastage, or a file that is about ninety-nine times as big as it should
// be ideally. In the smaller direction, 25 represents 25% wastage, or
// a file that is only 33% larger than it should be ideally.
//
// Callers can determine what policy they want to use for considering when
// a file holds too much wasted space, and express this as a percentage
// of total file size to pass as in the inPercentWaste parameter. A zero
// likely returns always trivially true, and 100 always trivially false.
// The great majority of callers are expected to use values from 25 to 75,
// since most plausible thresholds for compressing might fall between the
// extremes of 133% of ideal size and 400% of ideal size. (Presumably the
// larger a file gets, the more important the percentage waste involved, so
// a sliding scale for compress thresholds might use smaller numbers for
// much bigger file sizes.)
// } ----- end commit methods -----
// } ===== end nsIMdbPort methods =====
// { ===== begin nsIMdbStore methods =====
// { ----- begin table methods -----
NS_IMETHOD NewTable( // make one new table of specific type
nsIMdbEnv* ev, // context
mdb_scope inRowScope, // row scope for row ids
mdb_kind inTableKind, // the type of table to access
mdb_bool inMustBeUnique, // whether store can hold only one of these
const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying
nsIMdbTable** acqTable); // acquire scoped collection of rows
NS_IMETHOD NewTableWithOid( // make one new table of specific type
nsIMdbEnv* ev, // context
const mdbOid* inOid, // caller assigned oid
mdb_kind inTableKind, // the type of table to access
mdb_bool inMustBeUnique, // whether store can hold only one of these
const mdbOid* inOptionalMetaRowOid, // can be nil to avoid specifying
nsIMdbTable** acqTable); // acquire scoped collection of rows
// } ----- end table methods -----
// { ----- begin row scope methods -----
NS_IMETHOD RowScopeHasAssignedIds(nsIMdbEnv* ev,
mdb_scope inRowScope, // row scope for row ids
mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
mdb_bool* outStoreAssigned); // nonzero if store db assigned specified
NS_IMETHOD SetCallerAssignedIds(nsIMdbEnv* ev,
mdb_scope inRowScope, // row scope for row ids
mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
mdb_bool* outStoreAssigned); // nonzero if store db assigned specified
NS_IMETHOD SetStoreAssignedIds(nsIMdbEnv* ev,
mdb_scope inRowScope, // row scope for row ids
mdb_bool* outCallerAssigned, // nonzero if caller assigned specified
mdb_bool* outStoreAssigned); // nonzero if store db assigned specified
// } ----- end row scope methods -----
// { ----- begin row methods -----
NS_IMETHOD NewRowWithOid(nsIMdbEnv* ev, // new row w/ caller assigned oid
const mdbOid* inOid, // caller assigned oid
nsIMdbRow** acqRow); // create new row
NS_IMETHOD NewRow(nsIMdbEnv* ev, // new row with db assigned oid
mdb_scope inRowScope, // row scope for row ids
nsIMdbRow** acqRow); // create new row
// Note this row must be added to some table or cell child before the
// store is closed in order to make this row persist across sesssions.
// } ----- end row methods -----
// { ----- begin inport/export methods -----
NS_IMETHOD ImportContent( // import content from port
nsIMdbEnv* ev, // context
mdb_scope inRowScope, // scope for rows (or zero for all?)
nsIMdbPort* ioPort, // the port with content to add to store
nsIMdbThumb** acqThumb); // acquire thumb for incremental import
// Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
// then the import will be finished.
NS_IMETHOD ImportFile( // import content from port
nsIMdbEnv* ev, // context
nsIMdbFile* ioFile, // the file with content to add to store
nsIMdbThumb** acqThumb); // acquire thumb for incremental import
// Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
// then the import will be finished.
// } ----- end inport/export methods -----
// { ----- begin hinting methods -----
NS_IMETHOD
ShareAtomColumnsHint( // advise re shared column content atomizing
nsIMdbEnv* ev, // context
mdb_scope inScopeHint, // zero, or suggested shared namespace
const mdbColumnSet* inColumnSet); // cols desired tokenized together
NS_IMETHOD
AvoidAtomColumnsHint( // advise column with poor atomizing prospects
nsIMdbEnv* ev, // context
const mdbColumnSet* inColumnSet); // cols with poor atomizing prospects
// } ----- end hinting methods -----
// { ----- begin commit methods -----
NS_IMETHOD SmallCommit( // save minor changes if convenient and uncostly
nsIMdbEnv* ev); // context
NS_IMETHOD LargeCommit( // save important changes if at all possible
nsIMdbEnv* ev, // context
nsIMdbThumb** acqThumb); // acquire thumb for incremental commit
// Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
// then the commit will be finished. Note the store is effectively write
// locked until commit is finished or canceled through the thumb instance.
// Until the commit is done, the store will report it has readonly status.
NS_IMETHOD SessionCommit( // save all changes if large commits delayed
nsIMdbEnv* ev, // context
nsIMdbThumb** acqThumb); // acquire thumb for incremental commit
// Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
// then the commit will be finished. Note the store is effectively write
// locked until commit is finished or canceled through the thumb instance.
// Until the commit is done, the store will report it has readonly status.
NS_IMETHOD
CompressCommit( // commit and make db physically smaller if possible
nsIMdbEnv* ev, // context
nsIMdbThumb** acqThumb); // acquire thumb for incremental commit
// Call nsIMdbThumb::DoMore() until done, or until the thumb is broken, and
// then the commit will be finished. Note the store is effectively write
// locked until commit is finished or canceled through the thumb instance.
// Until the commit is done, the store will report it has readonly status.
// } ----- end commit methods -----
// } ===== end nsIMdbStore methods =====
};
//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789
#endif /* _ORKINSTORE_ */