wtest.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 <platform.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "wddb.h"

#define DB_MEMORY_SIZE  4 * 1024 * 1024
#ifndef MCO_PLATFORM_X64
#define PAGESIZE        96
#else
#define PAGESIZE        192 
#endif


const int MAP_ADDRESS =  0x20000000;

static int char_to_wchar(nchar_t *wbuff, const char* sbuff, int max_len) {
	int i;
	for(i = 0; i < max_len; i++) {
		wbuff[i] = ((uint2)sbuff[i] | 0x1a00);
		if (!sbuff[i]) break;
	}
	return i;
}

static char* nchar_to_char(nchar_t *wbuff, int len) {
	static char buffer[500];
	int i;
	for(i = 0; i < len && wbuff[i]; i++) {
		buffer[i] = (char)(wbuff[i] & 0x00ff);
	}
	buffer[i] = 0;
	return buffer;
}

static void out_wchar(nchar_t *wbuff, int len) {
    int i;
    for(i = 0; i < len && wbuff[i]; i++)
	putchar((int)(wbuff[i] & 0x00ff));
}

#include "w_data.h"

/* Load data to the database */
int LoadData(mco_db_h db) {

	MCO_RET     rc;
	mco_trans_h t;
	int         i = 0, len;
	Record      Obj;
	nchar_t     wbuffer[100];

	struct emp_data* e_ptr = EmpData;
	
	while(e_ptr->name) {
	        /* let's store records in DB */
		/* begin the transaction  */
		rc = mco_trans_start(db,MCO_READ_WRITE,MCO_TRANS_FOREGROUND,&t);

		if (rc == MCO_S_OK) {

			/* allocate a new object */
			rc = Record_new(t, &Obj);

			if (rc == MCO_S_OK) {
				i++; 
			    	/* fill the attributes */
				Record_iNumber_put(&Obj, i);

				len = char_to_wchar(wbuffer, e_ptr->dep, 100);
				Record_ncCode_put(&Obj, wbuffer, len);

				len = char_to_wchar(wbuffer, e_ptr->name, 100);
				Record_nsName_put(&Obj,  wbuffer, len);

				len = char_to_wchar(wbuffer, e_ptr->dep, 100);
				Record_ncDepartment_put(&Obj,  wbuffer, len);

				len = char_to_wchar(wbuffer, e_ptr->job, 100);
				Record_nsJob_put(&Obj,  wbuffer, len);

				rc = mco_trans_commit(t);
			}
			else {

				printf("Couldn't allocate a new object\n");
				mco_trans_rollback(t);
			};

		}
		else {
			printf("Unable to start a transaction\n");
		};
	    e_ptr++;
	};
	return 1;
}


/* Show attrs of a record */
void ShowObj( Record* hObj) {
	nchar_t      buffer[500];
	uint4        i;
	uint2        len;

	Record_iNumber_get(hObj, &i);
	printf("# %d: Code='", i);

	Record_ncCode_get(hObj, buffer, 500);
	out_wchar(buffer, 8); printf("' Name=");

	Record_nsName_get(hObj, buffer, 500, &len);
	out_wchar(buffer, len); printf(" Department=");

	Record_ncDepartment_get(hObj, buffer, 500);
	out_wchar(buffer, 20); printf(" Job=");

	Record_nsJob_get(hObj, buffer, 500, &len);
	out_wchar(buffer, len); printf("\n");
};

/* Show data using tree-indexes routine */

void ShowData(mco_db_h db) {

	MCO_RET      rc;
	mco_trans_h  t;
	mco_cursor_t csr, csr2;
	Record   Obj;
	int          i,j;

	/* navigate downward thru the items from the first to the last */
	printf("List of the first 10 records:\n");

	/* open a transaction */
	rc = mco_trans_start(db,MCO_READ_ONLY,MCO_TRANS_FOREGROUND,&t);
	if ( rc == MCO_S_OK ) {

		/* open the cursor */
		rc = Record_I_Order_index_cursor(t, &csr);
		if (rc == MCO_S_OK ) {

			/* jump to the first record */
			rc = mco_cursor_first(t, &csr);

			/* take 10 items */
			for (i=0; i<10 && rc==MCO_S_OK; i++) {

				/* get record from cursor */
				rc = Record_from_cursor(t, &csr, &Obj);

				if (rc == MCO_S_OK) {

					/* show it */
					ShowObj(&Obj);

					/* move to the next item */
					rc = mco_cursor_next(t, &csr);
				};
			};
		}
		else {
			printf ("Unable to open a cursor");
		};

		/*  close the transaction */
		rc = mco_trans_commit(t);
	}
	else {
		printf ("Unable to open a transaction");
	};
	printf("\n");

	/* navigate upward thru the items from the last to the first */
	printf("List of the last 10 records:\n");

	/* open a transaction */
	rc = mco_trans_start(db,MCO_READ_ONLY,MCO_TRANS_FOREGROUND,&t);
	if ( rc == MCO_S_OK ) {

		/* open the cursor */
		rc = Record_I_Order_index_cursor(t, &csr);
		if (rc == MCO_S_OK ) {

			/* move to last item */
			rc = mco_cursor_last(t, &csr);

			/* show last 10 items */
			for (i=0; i<10 && rc==MCO_S_OK; i++) {

				/* get the record */
				rc = Record_from_cursor(t, &csr, &Obj);

				if (rc == MCO_S_OK) {

					/* show	it */
					ShowObj(&Obj);

					/* move to the next item */
					rc = mco_cursor_prev(t, &csr);
				};
			};
		}
		else {
			printf ("Unable to a open cursor");
		};
		rc = mco_trans_commit(t);
	}
	else {
		printf ("Unable to open a transaction");
	};
	printf("\n");

	/* looking for specified item */
	printf("Search for the first record, where department is QA\n");

	/* open a transaction */
	rc = mco_trans_start(db,MCO_READ_ONLY,MCO_TRANS_FOREGROUND,&t);
	if ( rc == MCO_S_OK ) {

		/* open the cursor */
		rc = Record_I_Department_index_cursor(t, &csr);
		if (rc == MCO_S_OK ) {

			nchar_t wbuf[100]; int len;
			len = char_to_wchar(wbuf, "QA", 2);

			/* search an item by key value */
			rc = Record_I_Department_search(t, &csr, MCO_EQ, wbuf, len);

			/* analyze the results */
			switch (rc) {
				case MCO_S_OK:
				{
					/* Item's found. Display it. */
					rc = Record_from_cursor(t, &csr, &Obj);

					if (rc == MCO_S_OK ) {
						ShowObj(&Obj);

						/* Locate it in the I_Index cursor */
						rc = Record_I_Index_locate(t, &csr2, &Obj);

						if (rc == MCO_S_OK) {

							/* And show next one */
							if ( mco_cursor_next(t, &csr2) == MCO_S_OK &&
								Record_from_cursor(t, &csr2, &Obj) == MCO_S_OK )
								ShowObj(&Obj);
						};
					};
				};break;
				case MCO_S_NOTFOUND:
					printf("Not found.\n");
					break;
				default:
					printf("Error while searching.\n");
					break;
			};
		}
		else {
			printf ("Unable to open a cursor");
		};

		/* close the transaction */
		rc = mco_trans_commit(t);
	}
	else {
		printf ("Unable to open a transaction");
	};
	printf("\n");


	/* using composite index I_DiffSum */
	printf( "List of all records from the department = R&D\n" );

	/* open a transaction */
	rc = mco_trans_start(db,MCO_READ_ONLY,MCO_TRANS_FOREGROUND,&t);
	if ( rc == MCO_S_OK ) {
		/* open the cursor */
		rc = Record_I_Department_index_cursor(t, &csr);
		if (rc == MCO_S_OK ) {

			nchar_t wbuf[100]; int len;

			/* Search for the first occurence */
			i = 1;
			len = char_to_wchar(wbuf, "R&D", 3);

			rc = Record_I_Department_search(t, &csr, MCO_EQ, wbuf, len);

			do {
				int cmp=0;

				/* compare the item */
				rc = Record_I_Department_compare(t, &csr, wbuf,len, &cmp);
				if ( rc == MCO_S_OK && cmp == 0 ) {

					/* get the record */
					rc = Record_from_cursor(t, &csr, &Obj);
					if ( rc == MCO_S_OK ) {

						/* Show the record */
						ShowObj(&Obj);

						/* move to the next record */
						rc = mco_cursor_next(t, &csr);
						i++;
					};
				}
				else {
					break;
				};

			} while (rc == MCO_S_OK);
		}
		else {
			printf ("Unable to open cursor");
		};

		/* close the tramsaction */
		rc = mco_trans_commit(t);

	}
	else {
		printf ("Unable to open transaction");
	};
	printf("\n");

	printf( "Alphabetical list\n");
	j=0;

	/* open a transaction */
	rc = mco_trans_start(db,MCO_READ_ONLY,MCO_TRANS_FOREGROUND,&t);
	if ( rc == MCO_S_OK ) {

		/* open the cursor */
		rc = Record_I_Name_index_cursor(t, &csr);
		if (rc == MCO_S_OK ) {

			/* jump to first record */
			rc = mco_cursor_first(t, &csr);

			/* take 10 first items */
			while( rc==MCO_S_OK ) {

				/* get a record from cursor */
				rc = Record_from_cursor(t, &csr, &Obj);

				if (rc == MCO_S_OK) {

					/* show it */
					ShowObj(&Obj);

					/* move to the next item */
					rc = mco_cursor_next(t, &csr);
				};
			}
		}
		else {
			printf ("Unable to open cursor");
		};

		/* close the tramsaction */
		rc = mco_trans_commit(t);

	}
	else {
		printf ("Unable to open a transaction");
	};
		printf("\n");
}


void _SH_(void) {

	char text[] = {
		"\nThis samples demonstartes various tree index operations\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 void errhandler( int n ) {
	printf( "\neXtremeDB fatal error: %d", n );
	getchar();
	exit( -1 );
}


int main( void ) {

	MCO_RET        rc;
	mco_db_h       db = 0;
	char * start_mem  = 0;
	const char * dbName = "wddb";
	mco_runtime_info_t info;
	int rs=1;

	_SH_();
	mco_get_runtime_info( &info);
	if ( info.mco_shm_supported ) {
		start_mem = (char*)MAP_ADDRESS;
	}
	else {
		start_mem = (char*)malloc(DB_MEMORY_SIZE);
		if (!start_mem) {
			printf("Couldn't allocated memory\n");
			exit (1);
		}
	};

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

	/* start db engine */
	if ( mco_runtime_start() != MCO_S_OK) {
		printf( "\nUnable to start database engine\n" );
		if ( !info.mco_shm_supported )
			free( start_mem );
		exit(-1);
	};

	/* Create a database, using first memory segment */
	rc = mco_db_open( dbName, wddb_get_dictionary(),
		start_mem, DB_MEMORY_SIZE, (uint2) PAGESIZE );

	if ( rc == MCO_S_OK ) {

		/* connect to the database, obtain a database handle */
		if ( mco_db_connect( dbName, &db ) == MCO_S_OK ) {

			/* if LoadData is OK than ShowData */
			if ( LoadData(db) ) {
				ShowData(db);rs=0;
			}
			else {
				printf("Unable to load data\n");
			};
		}
		else {
			printf( "Unable to connect database\n" );
		};

		/* disconnect from the database, db is no longer valid */
		if ( mco_db_disconnect( db ) != MCO_S_OK ) {
			rs=2;printf( "mco_db_disconnect(...) failed\n" );
		};

		/* destroys the memory manager */
		if ( mco_db_close( dbName ) != MCO_S_OK ) {
			rs=3;printf( "mco_db_close(...) failed\n" );
		};

	}
	else {
		printf( "\nerror creating database" );
	};

	/* free the memory */
	if ( !info.mco_shm_supported )
		free( start_mem );

	/* shutdown database engine */
	mco_runtime_stop();

	printf("\nPress Enter key to exit" );
	getchar();
	PROG_EXIT(rs);
}