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const std = @import("std");
const lmdb = @cImport(@cInclude("lmdb.h"));
const print = std.debug.print;
pub fn Lmdb(comptime KeySize: comptime_int) type {
_ = KeySize;
return struct {
pub fn init(comptime path: []const u8) @This() {
var res: @This() = undefined;
_ = lmdb.mdb_env_create(&res.env);
// mdb_env_set_maxreaders(env, 1);
// mdb_env_set_maxdbs(env, 1); // named databases
// mdb_env_set_mapsize(env, 1024*1024);
_ = lmdb.mdb_env_open(res.env, path.ptr, 0, 0o664);
// /*MDB_FIXEDMAP |MDB_NOSYNC |MDB_NOSUBDIR*/
_ = lmdb.mdb_txn_begin(res.env, null, 0, &res.txn);
_ = lmdb.mdb_dbi_open(res.txn, null, 0, &res.dbi);
return res;
}
pub fn deinit(self: @This()) void {
_ = lmdb.mdb_txn_commit(self.txn);
_ = lmdb.mdb_dbi_close(self.env, self.dbi);
_ = lmdb.mdb_env_close(self.env);
}
pub fn get(self: @This(), comptime T: type, key: []const u8) ?T {
var k = lmdb.MDB_val{
.mv_data = @ptrFromInt(@intFromPtr(key.ptr)),
.mv_size = key.len,
};
var v: lmdb.MDB_val = undefined;
const res = lmdb.mdb_get(self.txn, self.dbi, &k, &v);
if (res == 0 and v.mv_size == @sizeOf(T)) {
if (v.mv_data) |data| {
return @as(*T, @ptrFromInt(@intFromPtr(data))).*;
}
}
return null;
}
pub fn put(self: @This(), comptime T: type, key: []const u8, val: T) void {
var k = lmdb.MDB_val{
.mv_data = @ptrFromInt(@intFromPtr(key.ptr)),
.mv_size = key.len,
};
var v = lmdb.MDB_val{
.mv_data = @ptrFromInt(@intFromPtr(&val)),
.mv_size = @sizeOf(T),
};
const res = lmdb.mdb_put(self.txn, self.dbi, &k, &v, 0);
_ = res;
// return val;
}
env: ?*lmdb.MDB_env,
dbi: lmdb.MDB_dbi,
txn: ?*lmdb.MDB_txn,
};
}
pub fn main() !void {
var db = Lmdb(16).init("./db");
defer db.deinit();
var testKey = [_]u8{0} ** 16;
@memcpy(testKey[0..5], "abcde");
// @memcpy(testKey[5..10], "abcde");
const u_1 = db.get(u8, &testKey);
print("u1: {?}\n", .{u_1});
var u_2 = db.get(u8, "abcde" ++ "12345");
db.put(u8, "abcde" ++ "12345", u_2.? + 1);
u_2 = db.get(u8, "abcde" ++ "12345");
print("u2: {?}\n", .{u_2});
}
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