leveldb测试demo（C）

转载自GitHub emnl

#include <leveldb/c.h>
#include <stdio.h>

int main() {
    
    
    leveldb_t *db;
    leveldb_options_t *options;
    leveldb_readoptions_t *roptions;
    leveldb_writeoptions_t *woptions;
    char *err = NULL;
    char *read;
    size_t read_len;
    /******************************************/
    /* OPEN */
    options = leveldb_options_create();
    leveldb_options_set_create_if_missing(options, 1);
    db = leveldb_open(options, "testdb", &err);
    if (err != NULL) {
    
    
      fprintf(stderr, "Open fail.\n");
      return(1);
    }
    /* reset error var */
    leveldb_free(err); err = NULL;
    /******************************************/
    /* WRITE */
    woptions = leveldb_writeoptions_create();
    leveldb_put(db, woptions, "key", 3, "value", 5, &err);
    if (err != NULL) {
    
    
      fprintf(stderr, "Write fail.\n");
      return(1);
    }
    leveldb_free(err); err = NULL;
    /******************************************/
    /* READ */
    roptions = leveldb_readoptions_create();
    read = leveldb_get(db, roptions, "key", 3, &read_len, &err);
    if (err != NULL) {
    
    
      fprintf(stderr, "Read fail.\n");
      return(1);
    }
    printf("key: %s\n", read);
    leveldb_free(err); err = NULL;
    /******************************************/
    /* DELETE */
    leveldb_delete(db, woptions, "key", 3, &err);
    if (err != NULL) {
    
    
      fprintf(stderr, "Delete fail.\n");
      return(1);
    }
    leveldb_free(err); err = NULL;
    /******************************************/
    /* CLOSE */
    leveldb_close(db);
    /******************************************/
    /* DESTROY */
    leveldb_destroy_db(options, "testdb", &err);
    if (err != NULL) {
    
    
      fprintf(stderr, "Destroy fail.\n");
      return(1);
    }
    leveldb_free(err); err = NULL;
    return(0);
}