#include <stdio.h>
#include "buffer.h"

#define CHECK(m,e) {if (e) {printf("Error in %s=%d\n",m,e);return -1;}}

main() {

    int db1,db2;
    int nb,err;
    char old;
    void *ptr;

    InitBuffer();
    db1 = OpenFile("testdb1");
    printf("num blocks = %d\n",GetNumBlocks(db1));
    err = GetBlock(db1,0,&ptr);
    printf("GetBlock 0 = %d\n",err);
    if (!err) {
	err = ReleaseBlock(db1,0,1);
	CHECK("ReleaseBlock",err);
    }

    err = AppendBlock(db1,&ptr);
    CHECK("AppendBlock",err);
    printf("num blocks = %d\n",nb=GetNumBlocks(db1));
    memset(ptr,'A',BLOCK_SIZE);
    err = ReleaseBlock(db1,nb-1,1);
    CHECK("ReleaseBlock",err);

    err = AppendBlock(db1,&ptr);
    CHECK("AppendBlock",err);
    printf("num blocks = %d\n",nb=GetNumBlocks(db1));
    memset(ptr,'B',BLOCK_SIZE);
    err = ReleaseBlock(db1,nb-1,1);
    CHECK("ReleaseBlock",err);

    err = GetBlock(db1,0,&ptr);
    CHECK("GetBlock",err);
    old = *(char *)ptr;
    printf("Block 0 contains %c\n",old);
    memset(ptr,old+2,BLOCK_SIZE);
    err = ReleaseBlock(db1,0,1);
    CHECK("ReleaseBlock",err);

    printf("num blocks = %d\n",nb=GetNumBlocks(db1));
    err = TruncateFile(db1,nb-2);
    CHECK("TruncateFile",err);
    printf("num blocks = %d\n",nb=GetNumBlocks(db1));

    err = CloseFile(db1);
    CHECK("CloseFile",err);
}