エージェントの例

例-1は、ファイルを表すリソースを管理するためのエージェント実装の詳細を説明しています。

例G-1 demoagent1.cpp

/* Copyright (c) 2004, 2012, Oracle and/or its affiliates.
All rights reserved. */

/*
 * NAME
 * Demoagent1.cpp: Demonstrates agent to monitor a file
 *
 * DESCRIPTION
 * This is a sample program that demonstrates an agent to monitor
 * a file. The agent has the following tasks:
 *  - On startup         : Create the file.
 *  - On shutdown        : Delete the file.
 *  - On check command   : Detect whether the file is present or not.
 *  - On clean command   : Delete the file.
 * This program can be used as a basis to build up more complicated
 * agents that manage real-world resources.
 *


#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <clsagfw.h>

エージェント・フレームワークclsagfw.hヘッダー・ファイルを含めます。

#define TEST_TYPE1                   (oratext *) "HOTFILE_TYPE"
#define TEST_PATHNAME_ATTR           (oratext *) "PATH_NAME"


/*
 * NAME
 *    test_agent_exit
 * DESCRIPTION
 *    Function to clean up, called by framework whenever the agent
 *    process is about to terminate
 * PARAMS
 *    exitCode, which is an sb4 describing the reason for exit.
 * RETURNS
 *    void
 */
void
test_agent_exit(sb4 exitCode)
{
  clsagfw_log(NULL, 1, (oratext *)"Demo Agent is exiting..\n");
}

エージェント・フレームワークに登録されているコールバック・ファンクションを終了します。

/*
 * NAME
 *    type1_start
 * DESCRIPTION
 *    Action entry point for the 'start' command. Creates the file for
 *    monitoring.
 * PARAMS
 *    Pointer to the agent framework context
 * RETURNS
 *    ub4 which could be CLSAGFW_AE_FAIL or CLSAGFW_AE_SUCCESS
 *    depending on whether the action failed or succeeded.
 */
ub4
type1_start(const clsagfw_aectx *ectx)
{
    ub4  ret = CLSAGFW_AE_FAIL;
    const oratext   *pResName  = NULL;
    const oratext   *pPathName = NULL;
    FILE *fp;

    clsagfw_log(ectx, 1, (oratext *)"Start action called..");

    /* Try to read the resource name */
    if (clsagfw_get_attrvalue(ectx, (oratext *)"NAME", &pResName) !=
            CLSAGFW_SUCCESS)
    {
      goto done;
    }

    /* Try to read the PATH_NAME attribute */
    if (clsagfw_get_attrvalue(ectx, TEST_PATHNAME_ATTR, &pPathName) !=
            CLSAGFW_SUCCESS)
    {
      goto done;
    }

clsagfw_get_attrvalue()を使用してリソース名およびPATH_NAME属性の名前を取得します。

    clsagfw_log(ectx, 1,
                (oratext *)"Start action arguments: resName = %s,
                pathName = %s", pResName, pPathName);

    /* Try to create the file */
    fp = fopen((char *)pPathName, "w");

    if(!fp)
    {
      /* Could not create the file */
        clsagfw_log(ectx, 1, (oratext *) "START action for resource %s:
                    FAILED\n", pResName);
        ret = CLSAGFW_AE_FAIL;
    }
    else
    {
      /* Created the file successfully */
        clsagfw_log(ectx, 1, (oratext *) "START action for resource %s: 
                    SUCCESS\n", pResName);
        ret = CLSAGFW_AE_SUCCESS;
      fclose(fp);
    }

done:
    return ret;
}

clsagfw_log()をコールすると、診断メッセージおよびエラー・メッセージのログがエージェント・ログ・ファイルに記録されます。

/*
 * NAME
 *    type1_stop
 * DESCRIPTION
 *    Action entry point for the 'stop' and 'clean' commands. Deletes
 *    the file being monitored.
 * PARAMS
 *    Pointer to agent framework context
 * RETURNS
 *    ub4 which could be CLSAGFW_AE_FAIL or CLSAGFW_AE_SUCCESS
 *    depending on whether the action failed or succeeded.
 */
ub4
type1_stop (const clsagfw_aectx *ectx)
{
    ub4             ret = CLSAGFW_AE_FAIL;
    const oratext   *pResName  = NULL;
    const oratext   *pPathName = NULL;

    clsagfw_log(ectx, 1, (oratext *)"Stop action called..");

    /* Try to read the resource name */
    if (clsagfw_get_attrvalue(ectx, (oratext *)"NAME", &pResName) !=
            CLSAGFW_SUCCESS)
    {
      clsagfw_log(ectx, 1, (oratext *)"STOP action: %s: Could not
                  read attribute\n", pResName);
      goto done;
    }

    /* Try to read the PATH_NAME attribute */
    if (clsagfw_get_attrvalue(ectx, TEST_PATHNAME_ATTR, &pPathName) !=
            CLSAGFW_SUCCESS)
    {
        pPathName = pResName;
    }

    clsagfw_log(ectx, 1,
                (oratext *)"Stop action arguments: resName = %s,
                pathName = %s", pResName, pPathName);

    /* Try to delete the file */
    if (remove((char *)pPathName))
    {
      /* Could not delete the file */
      clsagfw_log(ectx, 1, (oratext *)"STOP action for resource %s:
                  FAILED\n", pResName);
      ret = CLSAGFW_AE_FAIL;
    }
    else
    {
      /* Deleted the file successfully */
      clsagfw_log(ectx, 1, (oratext *)"STOP action for resource %s:
                  SUCCESS\n", pResName);
      ret = CLSAGFW_AE_SUCCESS;
    }

done:
    return ret;
}

/*
 * NAME
 *    type1_check
 * DESCRIPTION
 *    Action entry point for the 'check' command. Determines if the
 *    file exists.
 * PARAMS
 *    Pointer to agent framework context.
 * RETURNS
 *    ub4 which gives the status of the resource. Check the
 *    agent framework reference for details on this function's
 *     return codes.
 */
ub4 
type1_check(const clsagfw_aectx *ectx)
{
    ub4             ret = CLSAGFW_UNKNOWN;
    const oratext   *pResName  = NULL;
    const oratext   *pPathName = NULL;
    FILE *fp;

    clsagfw_log(ectx, 1, (oratext *)"Check action called..");

    /* Try to read the resource name */
    if (clsagfw_get_attrvalue(ectx, (oratext *) "NAME", &pResName) !=
            CLSAGFW_SUCCESS)
    {
      goto done;
    }

    /* Try to read the PATH_NAME attribute */
    if (clsagfw_get_attrvalue(ectx, TEST_PATHNAME_ATTR, &pPathName) !=
            CLSAGFW_SUCCESS)
    {
      clsagfw_log(ectx, 1, (oratext *)"CHECK action: %s: Could not
                  read attribute\n", pResName);
      goto done;
    }

    clsagfw_log(ectx, 1,
                (oratext *)"Check action arguments: resName = %s,
                pathName = %s", pResName, pPathName);

    /* Check if the file is accessible */
    fp = fopen((char *)pPathName, "r");
    if (!fp)
    {
      /* Could not open file */
      clsagfw_log(ectx, 1, (oratext *)"CHECK action: %s status –
                  UNPLANNED_OFFLINE\n", pResName);
      ret = CLSAGFW_UNPLANNED_OFFLINE;
    }
    else
    {
      /* Opened file successfully */
      clsagfw_log(ectx, 1,(oratext *)"CHECK action: %s status –
                  ONLINE\n", pResName);
      fclose(fp);
      ret = CLSAGFW_ONLINE;
    }

done:
    return ret;
}

/*
 * Initialization of the agent framework and registration of types is
 *  done in main.
 */
int main(sb4 argc, oratext **argv)
{
    clsagfw_log(NULL, 1, (oratext *)" *** Agent Framework Demo Agent
                Started *** \n");

    /*
     * Initialize the agent framework
     */
    if (clsagfw_init(argc, argv, 0, NULL, 0)
        != CLSAGFW_SUCCESS)
    {
      clsagfw_log(NULL, 1, (oratext *)"Failed to initilize the agent
                  framework\n");
      clsagfw_exit(-1);
    }

    /*
     * Set the exit callback function
     */
    clsagfw_set_exitcb(test_agent_exit);

    /*
     * Add the type definition to the framework
     */ 
    if (clsagfw_add_type(TEST_TYPE1) != CLSAGFW_SUCCESS)
    {
      clsagfw_log(NULL, 1,(oratext *)"Failed in adding type %s to the
                  framework\n", TEST_TYPE1);
      clsagfw_exit(-1);
    }


    /*
     * Set all entry points for for HOTFILE_TYPE
     */
    clsagfw_set_entrypoint(TEST_TYPE1, type1_start,
                           CLSAGFW_ACTION_START);
    clsagfw_set_entrypoint(TEST_TYPE1, type1_stop,
                           CLSAGFW_ACTION_STOP);
    clsagfw_set_entrypoint(TEST_TYPE1, type1_check,
                           CLSAGFW_ACTION_CHECK);
    clsagfw_set_entrypoint(TEST_TYPE1, type1_stop,
                           CLSAGFW_ACTION_CLEAN);

    clsagfw_log(NULL, 1, (oratext *)"Added resource type [%s] to the
                agent framework\n", TEST_TYPE1);

    /*
     * All set to go, Start the framework. This function does not
     * return if the framework starts successfully.
     */
    clsagfw_startup();

    /*** NOT REACHED **/

    return 0;
}