/* Opening or Creating a database */
DB *db_open(const char *pathname, int oflag, int mode)
{
DB *db;
int i, len;
char asciiptr[PTR_SZ + 1], hash[(NHASH_DEF + 1) * PTR_SZ +2]; /* +2 for newline and NULL */
struct stat statbuff;
/* Allocating a Database structure and the buffer it requires. */
len = strlen(pathname);
if((db = _db_alloc(len)) == NULL)
err_dump("error");
db->oflag = oflag; /* saving a copy of the open flags */
/* Opening index file */
strcpy(db->name, pathname);
strcat(db->name, ".idx");
if((db->idxfd = open(db->name, oflag, mode)) < 0)
{
_db_free(db);
return(NULL);
}
/* Opening data file */
strcpy(db->name + len, ".dat");
if((db->datfd = open(db->name, oflag, mode)) < 0)
{
_db_free(db);
return(NULL);
}
/* If the database was created, then initialize it */
if((oflag & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
{
/* write lock the entire file and so that, we can stat the file, check it's size & initialize it */
if(writew_lock(db->idxfd, 0, SEEK_SET, 0) < 0)
err_dump("error");
if(fstat(db->idxfd, &statbuff) < 0)
err_sys("error");
if(statbuff.st_size==0)
{
/*
We gotta build a list of (NHASH_DEF + 1) chain ptr with a value of 0.
The +1 is for free list pointer that precedes the hash table.
*/
sprintf(asciiptr, "%*d", PTR_SZ, 0);
hash[0] = 0;
for(i=0;i<(NHASH_DEF + 1);i++)
strcat(hash, asciiptr);
strcat(hash, "\n");
i = strlen(hash);
if(write(db->idxfd, hash, i) != i)
err_dump("error");
}
if(un_lock(db->idxfd, 0, SEEK_SET, 0) < 0)
err_dump("error");
}
db->nhash = NHASH_DEF; /* hash table size */
db->hashoff = HASH_OFF; /* offset in index file of hash table */
/* free list ptr always at FREE_OFF */
db_rewind(db);
return(db);
}
int ag_db_rewind(unsigned dbh)
{ return db_rewind(h2p(dbh));
}
int main(int argc, char **argv) {
DBHANDLE db;
int rc,c, flags, len;
char *ptr_command, *ptr_key, *find;
char *command, *key, *value;
command = key = value = NULL;
char *help_cmd = "command list:\n [add | update] key value \n [del | find] key \n [open | close] dbname\n [help count iterate exit]";
flags = O_RDWR;
while ((c = getopt(argc, argv, "nt?")) != -1) {
switch (c) {
case 'n':
flags |= O_CREAT;
break;
case 't':
flags |= O_TRUNC;
break;
case '?':
err_quit("usage: [-n] create new file [-t] truncate db <filename>");
break;
}
}
if (optind != argc - 1) {
err_quit("usage: [-n] create new file [-t] truncate db <filename>");
}
if ((db = db_open(argv[optind], flags, FILE_MODE)) == NULL) {
err_sys("db_open %s error", argv[optind]);
}
for (;;) {
char buf[MAX_LEN];
printf("APUEDB> ");
if (fgets(buf, MAX_LEN, stdin) == NULL) {
printf("Bye~\n");
exit(1);
}
to_lowercase(buf);
len = strlen(buf);
if ((ptr_command = strchr(buf,COMMAND_SEP)) == NULL) {
buf[len-1] = '\0';
if (strcmp(buf,"help") == 0) {
printf("%s\n", help_cmd);
continue;
} else if (strcmp(buf, "count") == 0) {
printf("%d\n", db_count(db));
} else if (strcmp(buf, "iterate") == 0) {
char *ptr;
db_rewind(db);
while ((ptr = db_nextrec(db, NULL)) != NULL) {
printf("%s\n", ptr);
}
continue;
} else if (strcmp(buf, "exit") == 0) {
printf("Bye~\n");
exit(1);
} else {
printf("invalid command, use command help for help\n");
continue;
}
}
command = strndup(buf, ptr_command - buf);
if (strcmp(command, "add") == 0) {
if ((ptr_key = strchr(ptr_command+1, COMMAND_SEP)) == NULL) {
printf("invalid add command, usage: add key value\n");
} else {
key = strndup(ptr_command+1, ptr_key - ptr_command - 1);
value = strndup(ptr_key+1, buf + len - 1 - ptr_key - 1);
rc = db_store(db, key, value, DB_INSERT);
if (rc == 0) {
printf("add +OK\n");
} else {
printf("key %s already exist\n", key);
}
}
} else if (strcmp(command, "update") == 0) {
if ((ptr_key = strchr(ptr_command+1, COMMAND_SEP)) == NULL) {
printf("invalid add command, usage: add key value\n");
} else {
key = strndup(ptr_command+1, ptr_key - ptr_command - 1);
value = strndup(ptr_key+1, buf + len - 1 - ptr_key - 1);
rc = db_store(db, key, value, DB_REPLACE);
if (rc == 0) {
printf("update +OK\n");
} else {
printf("key %s not found\n", key);
}
}
} else if (strcmp(command, "del") == 0) {
if ((ptr_key = strchr(ptr_command+1, COMMAND_SEP)) != NULL) {
printf("invalid del command, usage: del key\n");
continue;
}
key = strndup(ptr_command+1, buf + len - 1 - ptr_command -1);
rc = db_delete(db, key);
if (rc == 0) {
printf("del +OK\n");
} else {
printf("key %s not found\n", key);
}
} else if (strcmp(command, "find") == 0) {
if ((ptr_key = strchr(ptr_command+1, COMMAND_SEP)) != NULL) {
printf("invalid find command, usage: find key\n");
continue;
}
key = strndup(ptr_command+1, buf + len - 1 - ptr_command -1);
find = db_fetch(db, key);
if (find != NULL) {
printf("%d,%s\n", strlen(find), find);
} else {
printf("key %s not found\n", key);
}
}
if (key != NULL) {
free(key);
key = NULL;
}
if (command != NULL) {
free(command);
command = NULL;
}
if (value != NULL) {
free(value);
value = NULL;
}
}
}