shmdemo.c

eXtremeDB数据库在Linux平台下的使用源码。内含多个示例程序

/*****************************************************************
 *                                                               *
 * Copyright (c) 2001-2007 McObject LLC. All Right Reserved.     *
 *                                                               *
 *****************************************************************/

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

#include "shmdb.h"

const char  * dbname   = "demoShmDb";
const int   SEGSZ    = 1024 * 1024 * 10;		  // 10M
#ifndef MCO_PLATFORM_X64
static const int        PAGESIZE = 96;
#else
static const int        PAGESIZE = 192;
#endif


const int MAP_ADDRESS =  0x20000000;
int test_rc = MCO_S_OK;

void SH(void) {

	char text[] = {
		"\nThis sample demonstrates eXtremeDB shared memory interfaces\n"
	};
	char text1[] = {
		"Copyright (c) 2001-2007 McObject LLC. All Right Reserved.\n\n"
	};

	printf("%s\neXtremeDB runtime version %d.%d, build %d\n%s\n\nPress Enter to start",
		text, MCO_COMP_VER_MAJOR, MCO_COMP_VER_MINOR, MCO_COMP_BUILD_NUM,text1);

	getchar();

}


static int askNumber(const char *prompt) {
	char buf[300];
	printf("\n%s ", prompt);
	fgets(buf, sizeof (buf), stdin);
	if(isdigit(buf[0]))
		return atoi(buf);
	return -1;
}


static int hex2num(const char *s) {
	unsigned int a = 0;

	while(*s) {
		int n;
		if( *s >= '0' && *s <= '9' )
			n = *s - '0';
		else if( *s >='a' && *s <= 'f')
			n = *s - 'a' + 10;
		else if( *s >='A' && *s <= 'F')
			n = *s - 'A' + 10;
		else return a;

		a = (a << 4) | n;

		s++;
	}
	return a;
}


static int askHex(const char *prompt) {
	char buf[300];
	printf("\n%s ", prompt);
	fgets(buf, sizeof (buf), stdin);
	return hex2num(buf);
}


static void insertRec(mco_db_h db) {
	MyClass       c;
	MCO_RET       rc;
	mco_trans_h     t;
	int           id;
	char          str1[100], str2[100];

	id = askNumber("Enter new record's id:");
	mco_trans_start( db, MCO_READ_WRITE, MCO_TRANS_FOREGROUND, &t );
	MyClass_new(t, &c);
	sprintf(str1,"String1: %d", id);
	sprintf(str2,"String2: %d", id);
	MyClass_id_put(&c,(uint4)id);
	MyClass_str1_put(&c, str1, (uint2)strlen(str1) );
	MyClass_str2_put(&c, str2, (uint2)strlen(str2) );
	rc = mco_trans_commit(t);
	if(rc==MCO_S_OK)
		printf("\ninsert done for %d (%s, %s)\n",(int)id,str1,str2);
	else
		printf("\ninsert failed (%d) for %d (%s, %s)\n",rc,(int)id,str1,str2);
	if (test_rc==MCO_S_OK) test_rc=rc;
}


static void deleteRec(mco_db_h db) {
	MyClass       c;
	MCO_RET       rc;
	mco_trans_h     t;
	int           id;
	char          str1[100]= {0}
				, str2[100]= {0};

	id = askNumber("deleting record, Enter record's id:");
	mco_trans_start( db, MCO_READ_WRITE, MCO_TRANS_FOREGROUND, &t );
	rc = MyClass_pkey_find(t, (uint4)id, &c);
	if(rc != MCO_S_OK) {
		printf("\nRecord with id = %d not found\n", (int)id);
		mco_trans_rollback(t);
		return;
	}
	MyClass_str1_get(&c,str1,(uint2)sizeof(str1),0);
	MyClass_str2_get(&c,str2,(uint2)sizeof(str2) );
	rc = MyClass_delete(&c);
	
	if(rc == MCO_S_OK)
		rc = mco_trans_commit(t);
	else
		mco_trans_rollback(t);
		
	if(rc==MCO_S_OK)
		printf("\ndelete done for %d (%s, %s)\n",id,str1,str2);
	else
		printf("\ndelete failed (%d) for %d (%s, %s)\n",rc,id,str1,str2);
	if (test_rc==MCO_S_OK) test_rc=rc;
}


static void searchRec(mco_db_h db) {
	MyClass       c;
	MCO_RET       rc;
	mco_trans_h     t;
	int           id;
	char          str1[100]= {0}
				, str2[100]= {0};

	id = askNumber("searching record, Enter record's id:");
	mco_trans_start( db, MCO_READ_ONLY, MCO_TRANS_FOREGROUND, &t );
	rc = MyClass_pkey_find(t, (uint4)id, &c);
	if(rc != MCO_S_OK) {
		printf("\nRecord with id = %d not found\n", id);
		mco_trans_rollback(t);
		if (test_rc==MCO_S_OK) test_rc=-1;
		return;
	}
	MyClass_str1_get(&c,str1,(uint2)sizeof(str1),0);
	MyClass_str2_get(&c,str2,(uint2)sizeof(str2) );
	mco_trans_rollback(t);
	printf("\nrecord found: %d (%s, %s)\n",id,str1,str2);
}


static void listRecs(mco_db_h db) {
	MyClass       c;
	MCO_RET       rc;
	mco_trans_h     t;
	uint4         id;
	char          str1[100]= {0}
				, str2[100]= {0};
	mco_cursor_t  csr;

	mco_trans_start( db, MCO_READ_ONLY, MCO_TRANS_FOREGROUND, &t );

	MyClass_pkey_index_cursor( t, & csr );
	rc = mco_cursor_first(t, &csr);
	printf("\n----------- All records of type MyClass: -------- \n" );
	for( ; rc == MCO_S_OK; rc = mco_cursor_next(t, &csr) ) {
		rc = MyClass_from_cursor(t, &csr, &c);
		if(rc) {
			printf("\nUnexpected error %d\n",rc); break;
		}
		MyClass_id_get(&c, &id);
		MyClass_str1_get(&c,str1,(uint2)sizeof(str1),0);
		MyClass_str2_get(&c,str2,(uint2)sizeof(str2) );
		printf("record: %7d (%s, %s)\n",(int)id,str1,str2);
	}
	printf(  "------------------------ end of list ------------ \n");
	mco_trans_rollback(t);
}


static void menu( mco_db_h db ) {
	char          ibuf[300];
	int           ch;         // menu choice
	int				skip = 0;

	for(;;) {

		if (!skip)
		printf("\n----------------------------\nMenu:\n"
			"0:   exit\n"
			"1:   insert a record\n"
			"2:   delete a record\n"
			"3:   search a record\n"
			"4:   list records\n"
			"5:   print db statistics\n"
			"$ "
			);

		ibuf[0]=0;
		fgets(ibuf, sizeof (ibuf), stdin);
		if( (skip=! isdigit( ibuf[0] )) )
			continue;

		ch = atoi(ibuf);

		switch(ch) {
			default:
				break;
			case 0:
                                return;
			case 1:
				insertRec(db); break;
			case 2:
				deleteRec(db); break;
			case 3:
				searchRec(db); break;
			case 4:
				listRecs(db); break;
			case 5:
			{
				uint4 freepg, totalpg, nused;
				mco_db_free_pages   (db, &freepg);
				mco_db_total_pages  (db, &totalpg);

				nused = totalpg - freepg;

				printf("\nMemory:\n"
					"  %dKb available, %dKb used\n",
					(int)(freepg * PAGESIZE / 1024), (int)(nused * PAGESIZE / 1024) );

			}
			break;
		}

	}											  // end for

}


static void errhandler( int n ) {
	printf( "\neXtremeDB fatal error: %d", n );
	getchar();
	exit( -1 );
}


int main( int na, char **aa) {
	MCO_RET       rc;
	mco_db_h      db;
	void        * start_mem = 0;
	char          prompt[300], buf[100];
	mco_runtime_info_t info;

	SH();
	mco_get_runtime_info( &info);
	if ( !info.mco_shm_supported ) {
		printf("\nThis program requires shared memory database runtime\n");
		exit(1);
	};

	mco_runtime_start();

	/* set fatal error handler */
	mco_error_set_handler( &errhandler );

	printf("\nWould you like to create a new database [Y] or attach [N] -- [Y/N] ?" );
	fgets(buf, sizeof (buf), stdin);

	if(buf[0] == 'y' || buf[0] == 'Y') {

		sprintf(prompt,"Enter hint address (default is %x):",
			(int) MAP_ADDRESS );

		start_mem = (void*) askHex(prompt);
		if( start_mem == 0 )
			start_mem = (void*) MAP_ADDRESS;

		printf("\nSHM Map address is %x\n", (int) start_mem );

		rc = mco_db_open( dbname, shmdb_get_dictionary(), start_mem, SEGSZ, PAGESIZE );
		if ( rc ) {
			printf("\nCould not create instance: %d\n", rc);
			exit( 1 );
		}
	}

	rc = mco_db_connect( dbname, &db );
	if ( rc ) {
		printf("\nCould not attach to instance: %d\n", rc);
		exit( 1 );
	}

	menu( db );

	// shutdown

	rc = mco_db_disconnect( db );
	rc = mco_db_close( dbname );

	mco_runtime_stop();
	
	return test_rc;

}