HData

HData is a JSON database solution written entirely in Node.JS. It's memory resident and doesn't corrupt with simultanious writes. Reads and writes are executed in the sequence they're requested, so no more wrong values.

Not only that, but you interact with the database entirely in JSON as well! You send queries and commands to the server in JSON, and the server responds in JSON. The data is saved in JSON internally and externally. It's JSON all around!

Documentation

Creating an HData server

Read server/README.md

Using the HData Node.JS module

Note: all promises can be accessed under conn.promises and follow the same syntax, except without the callback. Values are returned in the promise resolve (.then((value) => {})) and errors are passed through a reject event (.catch((err) => {}))

Example:

const HData = require('hdata').HData;
const conn = new HData();
conn.login("root", "changeme", function(res, err) {
    conn.getKey("test", "key", function(res2, err2) {
        console.log(res2);
    });
});

becomes:

const HData = require('hdata').HData;
const conn = new HData();
async function test() {
    await conn.promises.login("root", "changeme");
    console.log(await conn.promises.getKey("test", "key"));
}

Creating an HData connection

To just use the default values ({"host":"127.0.0.1","port":8888,"datadir":"./","cachecerts":true}):

const HData = require('hdata').HData;
const conn = new HData();

By default, HData makes a connection to 127.0.0.1:8888, but options can be passed like so:

const HData = require('hdata').HData;
const options = {
    "host": "example.com",
    "port": 8000,
    "datadir": "/var/www/app",
    "cachecerts": false
}
const conn = new HData(options);

conn.status(callback)

Returns the server's status and how many pending jobs it has, including the active one.

conn.status(function(res, err) {
    console.log(`Server (version ${res.version}) has the status: ${res.status}, and has ${res.jobs} pending jobs. ${res.tables} tables exist in the database. The hostname is ${res.hostname} and is on port ${res.port}.`);
});

conn.login(username, password, callback)

Logs the current HData object in as username to the server.

conn.login("root", "changeme", function(res, err) {
    if (res.status == "OK") {
        console.log(`Logged in as ${username}!`);
    } else {
        console.log("Invalid username or password");
    }
});

The following commands require you to be logged in:

conn.logout(callback);

Logs out the current HData object.

conn.logout(function(res, err) {
    console.log("Successfully logged out");
});

conn.createUser(username, password, permissions, callback)

Creates a user with a the username username, password password, and the permissions given in the permissions array. (Requires the currently logged in user to have the createuser permission, and you cannot grant permissions you do not have to this new user).

conn.createUser("testuser", "testpassword", ["getkey","setkey"], function(res, err) {
    if (res.status == "OK") {
        console.log("User created!");
    } else {
        console.log("Insufficient permissions");
    }
});

conn.deleteUser(username, callback)

Deletes the user specified by username. (Requires the currently logged in user to have the deleteuser permission).

conn.deleteUser("testuser", function(res, err) {
    if (res.status == "OK") {
        console.log("User deleted!");
    } else {
        console.log("Insufficient permissions");
    }
});

conn.getUser(username, callback)

Returns an object containing the properties of the user username. (Requires the currently logged in user to have the updateuser permission).

conn.getUser("testuser", function(res, err) {
    if (res.status == "OK") {
        console.log(res.value);
    } else {
        console.log("Insufficient permissions");
    }
});

conn.updateUser(username, property, content, callback)

Updates the property of username with the value of content in the authentication database. (Requires the currently logged in user to have the updateuser permission).

conn.updateUser("testuser", "tables", ["users"], function(res, err) {
    if (res.status == "OK") {
        console.log("User updated!");
    } else {
        console.log("Insufficient permissions");
    }
});

conn.updatePassword(username, password, callback)

Updates the password of the user username to password. (Users may update their own passwords without any permissions, however the currently logged in user must have the updateuser permission to update another user's password).

conn.updatePassword("testuser", "testpasswordtwo", function(res, err) {
    if (res.status == "OK") {
        console.log("Password updated!");
    } else {
        console.log("Insufficient permissions");
    }
});

conn.createTable(tableName, callback)

Creates a table with the name provided in tableName. Errors if a table of the same name exists. Requires the createtable permission.

conn.createTable("users", function(res, err) {
    if (!err) {
        if (res.status == "OK") {
            console.log("Table created!");
        } else {
            console.log(JSON.stringify(res));
        }
    } else {
        console.log(err);
    }
});

conn.deleteTable(tableName, callback)

Deletes the table with the name provided by tableName. Errors if no table exists with that name. Requires the deletetable permission and that the user have permissions for the table.

conn.deleteTable("users", function(res,err) {
    if (!err) {
        if (res.status == "OK") {
            console.log("Table deleted!");
        } else {
            console.log(JSON.stringify(res));
        }
    } else {
        console.log(err);
    }
});

conn.getKey(tableName, keyName, callback)

Gets the value of the key named keyName from the table named tableName. Errors if the key or table does not exist. Requires the getkey permission and that the user have permissions for the table.

conn.getKey("users", "herronjo", function(res,err) {
    if (!err) {
        console.log(res.value);
    } else {
        console.log(err);
    }
});

conn.setKey(tableName, keyName, content, callback)

Sets the value of the key named keyName from the table named tableName to the value in content. Errors if the table does not exist. content can be any type of data that can be stored in JSON. Requires the setkey permission and that the user have permissions for the table.

conn.setKey("users", "herronjo", {isCool:true}, function(res,err) {
    if (!err) {
        console.log(res);
    } else {
        console.log(err);
    }
});

conn.deleteKey(tableName, keyName, callback)

Deletes the key named keyName from the table named tableName. Errors if the table or key does not exist. Requries the deletekey permission and that the user have permissions for the table.

conn.deleteKey("users", "herronjo", function(res,err) {
    if (!err) {
        if (res.status == "OK") {
            console.log("Key deleted!");
        } else {
            console.log(res);
        }
    } else {
        console.log(err);
    }
});

conn.getTables(callback)

Returns a list of tables (that the user has access to) on the server.

conn.getTables(function(res, err) {
    if (!err) {
        console.log(res.value); //Should return an array ["table1","table2"]
    } else {
        console.log(err);
    }
});

conn.queryAll(evaluator, callback)

Queries the database over all tables and keys, matching them against the evaluator specified. Returns all matches, including what table they're in, their values, and the key name. evaluator is a standard JavaScript evaluator, such as key.startsWith("egg") && value.includes("br"), which would return all keys whose names start with "egg" and have a value containing "br". The following variables exist in the scope the evaluator is evaluated in: key, value, and table, which contain the key name, value of the key, and table the key is in respectively. Requires the getkey permission. Only queries tables the user has permission to read.

conn.queryAll('key.startsWith("egg") && value.includes("br")', function(res,err) {
    if (!err) {
        console.log(res.matches);
    } else {
        console.log(err);
    }
});

Returns something like: [{"table": "users", "key": "egg123", "value": "bruh moment"},{"table": "users", "key": "eggbot", "value": "bread is cool"}]

conn.queryTable(tableName, evaluator, callback)

Queries the database over just the table tableName and its keys, matching them against the evaluator specified. Returns all matches, including what table they're in, their values, and the key name. evaluator is a standard JavaScript evaluator, such as key.startsWith("egg") && value.includes("br"), which would return all keys whose names start with "egg" and have a value containing "br". The following variables exist in the scope the evaluator is evaluated in: key, value, and table, which contain the key name, value of the key, and table the key is in respectively. Requires the getkey permission and that the user have permissions for the table.

conn.queryTable("users", 'key.startsWith("egg") && value.includes("br")', function(res,err) {
    if (!err) {
        console.log(res.matches);
    } else {
        console.log(err);
    }
});

Returns something like the above example: [{"table": "users", "key": "egg123", "value": "bruh moment"},{"table": "users", "key": "eggbot", "value": "bread is cool"}]

conn.tableExists(tableName, callback)

Checks if the table tableName already exists in the database. Requires the getkey permission.

conn.tableExists("table", function(res,err) {
    if (!err) {
        if (res.value) {
            console.log("Table exists!");
        } else {
            console.log("Table does not exist");
        }
    } else {
        console.log(err);
    }
});

conn.tableSize(tableName, callback)

Returns the number of keys in the table tableName. Requires the getkey permission and that the user have permissions for the table.

conn.tableSize("table", function(res,err) {
    if (!err) {
        console.log("Table has "+res.size+" keys");
    } else {
        console.log(err);
    }
});

conn.tableKeys(tableName, callback)

Returns an array of the names of all keys in tableName. Requires the getkey permission and that the user have permissions for the table.

conn.tableKeys("table", function(res,err) {
    if (!err) {
        console.log("Table has the following keys: "+JSON.stringify(res.keys));
    } else {
        console.log(err);
    }
});

conn.getProperty(tableName, keyName, path, callback)

If the key keyName in the table tableName is an object, this returns the value of the property following the path provided by path. Paths look like the following: property (for an object like {property: "value"}), property.0 (for an object like {property: ["a", "b"]}), property.property2.property3 (for an object like {property: {property2: {property3: "value"}}}), 0 (for an array like ["a", "b", "c"]), etc.

conn.getProperty("table", "key", "herronjo.posts.0", function(res,err) {
    if (!err) {
        console.log("Got herronjo's post #0: "+JSON.stringify(res.value));
    } else {
        console.log(err);
    }
});

conn.setProperty(tableName, keyName, path, value, callback)

If the key keyName in the table tableName is an object, this sets the value of the property following the path provided by path. Paths look like the following: property (for an object like {property: "value"}), property.0 (for an object like {property: ["a", "b"]}), property.property2.property3 (for an object like {property: {property2: {property3: "value"}}}), 0 (for an array like ["a", "b", "c"]), etc.

conn.setProperty("table", "key", "herronjo.posts.0.title", "A wonderful test", function(res,err) {
    if (!err) {
        console.log("Updated herronjo's post #0 title");
    } else {
        console.log(err);
    }
});

Error codes

Status	Meaning
OK	All good, no errors
NLI	Not logged in
LI	Logged in
AERR	Auth error (incorrect username/password)
PERR	Permission error (you don't have permissions to do that)
UE	User already exists
UDNE	User doesn't exist
TE	Table already exists
TDNE	Table doesn't exist
KDNE	Key doesn't exist
EVERR	Evaluation error (error with evaluator when querying)