qt6-migration-pipeline/external/rti_connext_dds-7.7.0/include/ndds/reda/reda_table.h

/*
 * (c) Copyright, Real-Time Innovations, 2002-2026.
 * All rights reserved.
 * No duplications, whole or partial, manual or electronic, may be made
 * without express written permission.  Any such copies, or
 * revisions thereof, must display this notice unaltered.
 * This code contains trade secrets of Real-Time Innovations, Inc.
 */

#ifndef reda_table_h
#define reda_table_h

#include "osapi/osapi_type.h"
#include "reda/reda_dll.h"
#include "reda/reda_epoch.h"
#include "reda/reda_fastBuffer.h"

#ifdef __cplusplus
extern "C" {
#endif

/* Doxygen file & module documentation ==================================*/
/*e \file

    \brief Defines the REDATable
*/

/* ----------------------------------------------------------------- */
/*e \defgroup REDATableClass REDATable
  \ingroup REDAModule

  @brief a data structure that allows safe and efficient
  storage, iteration and search among fixed-size structures that are
  entered by the application. Each such structure is referred as a
  "record".

  The REDA model of a table is composed of three main elements: The
  table (REDATable) that holds records, cursors (REDACursor) that allow
  iteration and modification of records in the table, and weakReferences
  (REDAWeakReference) that allow caching a logical index to a record
  in the table.

  \image html Table_Overview_Public.jpg  "Overview of REDATable"

  Each record consists of three areas: a key, a readOnlyArea and
  a readWriteArea.  The format and size of these three areas is
  the same for all \e records in the table and is defined by
  providing REDAOrderedDataTypes when the table is created.
  REDATable requires the key to be unique accross all records in
  the table.  The key is used to provide efficient searching, using
  an underlying REDAHashedSkiplist.
  The readOnlyArea is written when a new record is added to the table
  and can never be modified.
  The readWriteArea of a record can be modified.

  REDATable is optimized for use in a multi-threaded environment where
  multiple threads may need to iterate as well as enter or remove
  records.  These operations are done through creating a REDACursor
  and binding it to a table.  Once a cursor has been succesfully bound
  to the table, all cursor-opertations are multi-thread safe.  Through
  a bound cursor, threads can modify the records and the table.

  The weakReference is a reference to a record of a table.  Such
  a reference is "weak" because the record can
  be removed even if there are weak-references to it.  In that case,
  dereferencing the weak-reference (with gotoWeakReference) will
  return an error.

  As most operations are done safely through a cursor, only three methods
  can be invoked on a table: REDATable_bindCursor, REDATable_cleanup
  and REDATable_delete.  When calling these methods on the REDATable itself,
  the caller has the responsability to make sure the table has not been
  deleted.  After REDATable_delete has been called, no methods can be
  called on that table any more; however, cursors that might still be
  bound to that table will be fine: they will refuse to start..

  \image html Table_States.jpg  "REDATable lifecycle"

  The life-line of a table can be illustrated in the pseudo-code below:
  \anchor DOXANCHOR_tableLifeline
  \code
  struct REDACursor *cursor;
  struct REDAWorker *worker;
  struct REDATable *table;
  struct REDAWorkerFactory *workerFactory;

  workerFactory = REDAWorkerFactory_new(...)
  worker = REDAWorkerFactory_createWorker(workerFactory, ...);
                                // or use a pre-existing one
  table = REDATable_new(...);   // create table
  REDATable_bindCursor(table, cursor, worker);
                                // initialize cursor and bind it

  REDACursor_start(cursor, ...);

  // find a record and read it
  REDACursor_gotoKeyEqual(cursor, );
  REDACursor_getReadOnlyArea(cursor, ...)

  // Find a record and modify it
  REDACursor_gotoKeyEqual(cursor, );
  REDACursor_modifyReadWriteArea(cursor, ...)
  REDACursor_finishReadWriteArea(cursor, ...)

  // Lock the table
  REDACursor_lockTable(cursor, ...);

  // Now we can insert & remove records, etc.
  REDACursor_assertAndModifyReadWriteArea(cursor, ...)

  // Remove a record
  REDACursor_gotoKeyEqual(cursor, );
  REDACursor_removeRecord(cursor, ...);

  // Indicate we are no longer using the cursor
  REDACursor_finish(cursor, );

  // The application can keep the cursor around and call _start()/_finish()
  // again to access more records
  REDACursor_start(cursor, ...);
  // Access more records...
  REDACursor_finish(cursor, ...);

  // The cursor can remove the entire table as follows
  REDACursor_start(cursor, ...);
  REDACursor_lockTable(cursor, ...);
  REDACursor_removeTable(cursor, ...);
  REDACursor_finish(cursor, ...);

  // For cleanup, the following method must be called regularly
  REDATable_cleanup(table, &tableCanBeDeleted,...)

  // Finally, the table can be deleted
  if(tableCanBeDeleted) {
      REDATable_delete(table,...)
  }

  // At this point: methods on the table CANNOT be invoked any more
  // BUT the cursors bound to the table will still be safe
  REDACursor_start(cursor, ...) // returns FALSE as the table has been deleted

  \endcode

  @see REDACursor REDAWeakReference
*/

/* Need to declare these so that we don't have to expose the internal
 * structures */
struct REDASkiplistDescription;
struct REDAExclusiveArea;
struct REDAOrderedDataType;
struct REDAHashDefinition;
struct REDACursor;
struct REDATable;
struct REDAWorker;
struct REDAWeakReferenceManager;

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass
  @brief Used to indicate that a default value should be used.

  Typically used
  as argument to functions that expect configuration parameters and
  hints such as number of records, hash-buckets, etc.
*/
#define REDA_TABLE_USE_DEFAULT_VALUE (-1)

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass
  @brief Used to indicate the maximum length of table name used for
  creating table.
*/
#define REDA_TABLE_NAME_MAX_LENGTH (80)

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass

  @brief Prototypes the function that can be registered to get notification
  that a table is physically removed from memory. This is the place
  where any resources that where loaned to the table may be
  freed. This function is specified in the \c tableFinalizeFnc
  argument to the REDATable_new function.

  This function will be called exactly once from the context of
  a thread calling REDATable_cleanup.  When the function has been
  called, no cursor can access the table any more and the table
  can be deleted with REDATable_delete.

  @param param \b In. The \c tableFinalizeParam specified when the
  table was created. See REDATable_new.

  @param recordFinalizeParam\b In. The \c recordFinalizeParam
  specified when the table was created. See REDATable_new.

  @param tableUserData\b In. The userData that was stored in the
  table on creation.  See REDATable_new.

  @param worker\b In. Reaper worker.

  @see REDATable_new
*/
typedef void (*REDATableFinalizeFunction)(
        void *param,
        void *recordFinalizeParam,
        void *tableUserData,
        struct REDAWorker *worker);

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass

  @brief Prototypes the function that can be registered to get notification
  that a record is physically removed from memory. This is the place
  where any resources that where inside the record may be freed.

  Prior to this function being called it may be possible for cursors
  to still access a removed record if they were positioned at the record
  or if there was a race condition. After this function is called, it is
  guaranteed that nobody can access the record and thus it is only
  now that we may finalize and release resources associated with the
  record.

  @param param\b In. The \c recordFinalizeParam specified when the
  table was created. See REDATable_new.

  @param key\b In.  The record's key

  @param readOnlyArea\b In.  The record's readOnlyArea

  @param readWriteArea\b In.  The record's readWriteArea

  @param worker\b In. Reaper worker.

  @mtsafety Safe. It is guaranteed that no other worker is using the record
  now and in future.  You may destroy at will.

  @see REDATable_new
*/
typedef void (*REDATableRecordFinalizeFunction)(
        void *param,
        void *key,
        void *readOnlyArea,
        void *readWriteArea,
        struct REDAWorker *worker);

/*  ===================================================================== */
/*e \defgroup REDATablePropertyClass REDATableProperty
  \ingroup REDATableClass
  @brief A convenient way to group properties of a table
  Note that this is not actually used in
 */
struct REDATableProperty {
    struct REDAFastBufferPoolGrowthProperty growth;
    int hashBucketCount;
};

/* --------------------------------------------------------------------- */
/*e \ingroup REDATableClass

  @brief Creates a REDATable.

  REDATable is implemented using a REDAHashedSkiplist for management
  of the records.  See REDAHahsedSkiplist for more information on
  the performance and memory usage implications of the hashing.

  @param tableName \b In. Name of table for debugging purpose. Can be NULL.

  @param keyType \b In. Defines the type of keys used to identify the
  records in the the table.  Must have been initialized with
  REDAOrderedDataType_define.  The relevant contents will be copied
  into the table; this structure can be deleted after the Table has
  been created.

  @param readOnlyAreaType \b In. Defines the type of data in the read-only
  area of the records.  Must have been initialized with
  REDAOrderedDataType_define or can be NULL in which case the Table does
  not have records with a readOnlyArea.
  The relevant contents will be copied into the table; this structure
  can be deleted after the Table has been created.

  @param readWriteAreaType \b In. Defines the type of data in the read-write
  area of the records.  Must have been initialized with
  REDAOrderedDataType_define OR can be NULL in which case the Table does not
  have records with a readWriteArea.
  The relevant contents will be copied into the table; this structure can
  be deleted after the Table has been created.

  @param hashDefinition \b In. Defines the hashing that will be used
  on the key.  See the documentation for REDAHashedSkiplist and REDAHash
  for more information.
  The relevant contents will be copied into the table; this structure
  can be deleted after the Table has been created.  In case this parameter
  is NULL, no hashing will be used.

  @param skiplistDesc \b In.  Describes the properties of the underlying
  hashedSkiplist.  This description is NOT copied into the table; it
  must remain in existence with the Table.

  @param weakRefManager \b In. a manager for the weak references. Must
  have been allocated with REDAWeakReferenceManager_new.  The
  WeakReferenceManager must remain in existence as long as the Table
  exists or weak-references to records of the Table might still be
  lying around in the application.  The WeakReferenceManager typically
  will be the last object to be destroyed in an application using Tables.

  @param tableEA \b In.  The table-level exclusive area.  It is necessary
  that a worker can enter the adminEA of the table, the adminEA of the
  weak-reference manager and the record EA's from within the tableEA.

  @param adminEA \b In.  The administrative EA: the table will use this
  EA for short internal protection.  This EA must be such that it can
  be entered from within any other EA: from within the table-EA and/or
  record-EA's.

  @param tableFinalizeFnc \b In. A function to be notified that the
  table is physically removed from memory and nobody is able to access
  it anymore. See REDATableFinalizeFunction for details.
  This parameter may be NULL if no finalization function is desired.

  @param tableFinalizeParam \b In. Parameter to pass to tableFinalizeFnc.

  @param recordFinalizeFnc \b In. Used to notify application when a
  record is about the be physically removed and nobody can access its
  contents.  See REDARecordFinalizeFunction for details.
  May be NULL to indicate there is no notification is needed.

  @param recordFinalizeParam \b In. Additional parameter to pass to
  recordFinalizeFnc.

  @param growthPropertyIn.  This is like the table's property.  Since there
    are no other meaningful table property, we just use this "parent" class
    directly.

  @param tableUserData \b In. Table provides storage space for one
  pointer, which can be retrieved safely through REDACursor_getTableUserData.
  The table only provides safe read-only access; this pointer or the
  structure it points cannot be modified without additional protection
  on top of the Table.

  @mtsafety Safe.

  @see REDACursor REDAWeakReferenceManager_new REDATable_cleanup
  REDATable_delete
*/
extern REDADllExport struct REDATable *REDATable_new(
        const char *tableName,
        const struct REDAOrderedDataType *keyType,
        const struct REDAOrderedDataType *readOnlyAreaType,
        const struct REDAOrderedDataType *readWriteAreaType,
        const struct REDAHashDefinition *hashDefinition,
        const struct REDASkiplistDescription *skiplistDesc,
        const struct REDAFastBufferPoolGrowthProperty *growthPropertyIn,
        struct REDAWeakReferenceManager *weakRefManager,
        struct REDAExclusiveArea *tableEA,
        struct REDAExclusiveArea *adminEA,
        REDATableFinalizeFunction tableFinalizeFnc,
        void *tableFinalizeParam,
        REDATableRecordFinalizeFunction recordFinalizeFnc,
        void *recordFinalizeParam,
        void *tableUserData);

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass

  @brief Get the read-only growth property of the table
  @mtsafety Safe.
*/
extern REDADllExport const struct REDAFastBufferPoolGrowthProperty *
REDATable_getGrowthProperty(struct REDATable *me);

/*e \ingroup REDATableClass

  @brief Get the read-only table name.
  @mtsafety Safe.
*/
extern REDADllExport const char *REDATable_getName(const struct REDATable *me);

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass

  @brief Deletes a REDATable.

  It is the responsability of the application that uses tables
  to ensure that after the call to REDATable_delete is made, no
  other methods (bindCursor, cleanup or delete) are invoked on this
  table.
  When the table is deleted when the precondition (see below) is met;
  the implementation guarantees that Cursors still bound to the
  Table will not be allowed to use the deleted Table and WeakReferences
  refering to records of the deleted Table are invalidated.

  @pre A valid (undeleted) Table; the table has been removed and
  REDATable_cleanup() has been called as many times as required until
  it sets the parameter tableCanBeDeleted to TRUE.

  @post The table is deleted.

  @param table \b In. The table to delete.

  @mtsafety Unsafe. Only one thread can call this method.

  @see REDACursor REDATable_new REDATable_cleanup
*/
extern REDADllExport void REDATable_delete(struct REDATable *table);

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass

  @brief Bind a new cursor to a specific table and worker.

  This function initializes the cursor and binds it to a table and
  worker. Cursors must be bound prior to be in used on tables. This
  function must be called before calling any other functions on the
  cursor, specifically REDACursor_start and any other functions that
  attempt to access a table.

  Refer to the \ref DOXANCHOR_CursorStates "cursor state diagram" for
  the role of this function within the cursor lifeline.

  This operation will fail if the table has been removed or if
  pre-condition checking is enabled it is detected that they
  are not met

  @pre cursor must point to enough memory to hold a (struct REDACursor).
       Cursor must be in state "unbound";
       Table must be a valid table. It can be removed but it cannot
       have benn deteted (i.e. REDATable_delete should have not been
       called on that table.

  @post on success (RTI_TRUE is returned): the cursor is bound to the
       table and worker and is in state "inactive".
    on failure (RTI_FALSE is returned) the cursor is left in the
       state UNBOUND.

  @param table \b In. The table to bind the cursor to

  @param cursor \b In. The cursor to bind. Cannot be NULL

  @param worker \b In. The worker under which context the cursor will
  operate

  @mtsafety unsafe. This call can only be made by one thread (worker) on any
  given cursor. Once bound then only that thread/worker can use the cursor.

  \code
  struct REDACursor cursor;
  struct *REDAWorker worker;
  struct *REDATable table;

  worker = REDAWorker_new(...); // or use a pre-existing one
  table = REDATable_new(...);   // create table
  if(!REDATable_bindCursor(table, &cursor, worker)) {
    // error-handling
  }

  // Now we can start and use the cursor:
  REDACursor_start(&cursor,...);        // declare intent of using the cursor
  \endcode

  @mtsafety Safe. As long as the table is undeleted, workers can concurrently
         bind to the table without affecting each other.

  @see REDACursor_start REDACursor_unbind
*/
extern REDADllExport RTIBool REDATable_bindCursor(
        struct REDATable *table,
        struct REDACursor *cursor,
        struct REDAWorker *worker);

/* ----------------------------------------------------------------- */
/*e \ingroup REDATableClass

  @brief Cleaning up will (if possible) delete the structures (records or the
  entire table) that have been removed through Cursors.

  The registered record- and table-finalization methods will also be
  called from this method right before the affected structures are
  removed from memory.

  The typical usage is to call this function at some period to "delete"
  the records that have been removed until the output parameter
  tableCanBeDeleted is TRUE and then, once we are sure the table will
  no longer be accessed, call Table_delete.

  This operation can be called in any of the table states:
  If the table is in the state Alive, then it will just delete the
  removed records that are no longer accessible by the bound cursors.
  If the table is in the state Removed, in addition to deleting the
  removed records that are innaccessible it will check whether the
  table can be removed and transition to the "CanBeDeleted" state.
  If the table is in the "CanBeDeleted" state, the operation will
  be a NOOP. It will however return RTI_TRUE and tableCanBeDeleted=TRUE.

  @pre A table in the Alive, Removed, or CanBeDeleted state.
       The table cannot have been deleted (by calling Table_delete)

  @invariant The logical contents of the table is not modified

  @param table \b in. A valid table to clean up.
  @param tableCanBeDeleted \b out.  An optional parameter; if RTI_TRUE
      is returned, the table is in the "CanBeDeleted" state and the
      operation REDATable_delete can be called to effectively delete the table
      without endangering the safety of any Cursors bound to the table.
  @param worker \b in. The worker that calls this function.

  @return RTI_TRUE on success, RTI_FALSE on failure

  @mtsafety Safe. As long as the table is undeleted, any worker can
    cleanup the table.

  @see REDACursor REDATable_delete
*/
extern REDADllExport RTIBool REDATable_cleanup(
        struct REDATable *table,
        RTIBool *tableCanBeDeleted,
        struct REDAWorker *worker);

/*e \defgroupREDATablePropertyClass
 * @brief A convenient way to form a table property from individual parameters
 *
 * @note This functions is implemented as a macro
 */
void REDATableProperty_init(
        struct REDATableProperty *me,
        int initial,
        int maximal,
        int growthIncrement,
        int hashBucketCount);

#ifdef __cplusplus
} /* extern "C" */
#endif

/* pick up hidden performance boosting macros and optimizations */
#include "reda/reda_table_impl.h"

#endif /* reda_table_h */