kvdex

kvdex is a high-level abstraction layer for Deno KV with zero third-party dependencies by default. It's purpose is to enhance the experience of using Deno's KV store through additional features such as indexing, strongly typed collections and serialization/compression, while maintaining as much of the native functionality as possible, like atomic operations, real-time data updates and queue listeners. Also works with other runtimes such as Node.js and Bun, and has compatibility options for the browser.

Supported Deno verisons: ^1.43.0

Highlights

• Strongly typed CRUD operations for selected and ranged documents.
• Primary (unique) and secondary (non-unique) indexing.
• Extensible model strategy (Zod supported).
• Serialized, compressed and segmented storage for large objects.
• Listen to real-time data updates.
• Support for pagination and filtering.
• Message queues at database and collection level with topics.
• Support for atomic operations.

Table of Contents

• kvdex
  • Highlights
  • Table of Contents
  • Models
  • Database
  • Collection Options
    • idGenerator
    • indices
    • encoder
    • history
  • Collection Methods
    • find()
    • findByPrimaryIndex()
    • findBySecondaryIndex()
    • findMany()
    • findHistory()
    • findUndelivered()
    • add()
    • addMany()
    • set()
    • update()
    • updateByPrimaryIndex()
    • updateBySecondaryIndex()
    • updateMany()
    • updateManyBySecondaryOrder()
    • updateOne()
    • updateOneBySecondaryIndex()
    • updateOneBySecondaryOrder()
    • upsert()
    • upsertByPrimaryIndex()
    • delete()
    • deleteByPrimaryIndex()
    • deleteBySecondaryIndex()
    • deleteMany()
    • deleteManyBySecondaryOrder()
    • deleteHistory()
    • deleteUndelivered()
    • getMany()
    • getManyBySecondaryOrder()
    • getOne()
    • getOneBySecondaryIndex()
    • getOneBySecondaryOrder()
    • forEach()
    • forEachBySecondaryIndex()
    • forEachBySecondaryOrder()
    • map()
    • mapBySecondaryIndex()
    • mapBySecondaryOrder()
    • count()
    • countBySecondaryIndex()
    • countBySecondaryOrder()
    • enqueue()
    • listenQueue()
    • watch()
    • watchMany()
  • Database Methods
    • countAll()
    • deleteAll()
    • wipe()
    • deleteUndelivered()
    • findUndelivered()
    • enqueue()
    • listenQueue()
    • setInterval()
    • loop()
    • atomic()
  • Atomic Operations
    • Without checking
    • With checking
  • Document Methods
    • flat()
  • Extensions
    • Encoding
      • JSON
      • V8
      • Brotli
    • Zod
      • Schemas
    • Migrate
      • Script
      • Function
    • KV
  • Blob Storage
  • Development
  • License

Models

Collections are typed using models. Standard models can be defined using the model() function. Alternatively, any object that is compatible with the Model type can be used as a model. Zod is therefore supported, without being a dependency. The standard model uses type casting only, and does not validate any data when parsing. Asymmetric models can be created by passing a transform function which maps from an input type to an output type. Asymmetric models are useful for storing derived values or filling default values. It is up to the developer to choose the strategy that fits their use case the best.

NOTE: When using interfaces instead of types, they must extend the KvValue type.

Using the standard model strategy:

import { model } from "@olli/kvdex";

type User = {
  username: string;
  age: number;
  activities: string[];
  address?: {
    country: string;
    city: string;
    street: string;
    houseNumber: number | null;
  };
};

// Normal model (equal input and output)
const UserModel = model<User>();

// Asymmetric model (mapped output)
const UserModel = model((user: User) => ({
  upperCaseUsername: user.username.toUpperCase(),
  ageInDecades: user.age / 10,
  createdAt: new Date(),
}));

Using Zod instead:

import { z } from "npm:zod";

type User = z.infer<typeof UserModel>;

const UserModel = z.object({
  username: z.string(),
  age: z.number(),
  activities: z.array(z.string()),
  address: z.object({
    country: z.string(),
    city: z.string(),
    street: z.string(),
    houseNumber: z.number().nullable(),
  }).optional(),
});

Database

kvdex() is used for creating a new database instance. It takes an options object which expects a Deno KV instance and a schema definition.

import { kvdex, model, collection } from "@olli/kvdex"
import { jsonEncoder } from "@olli/kvdex/encoding/json"

const kv = await Deno.openKv()

const db = kvdex({
  kv: kv,
  schema: {
    numbers: collection(model<number>()),
    serializedStrings: collection(model<string>(), {
      encoder: jsonEncoder()
    }),
    users: collection(UserModel, {
      history: true,
      indices: {
        username: "primary" // unique
        age: "secondary" // non-unique
      }
    }),
    // Nested collections
    nested: {
      strings: collection(model<string>()),
    }
  }
})

The schema definition contains collection builders, or nested schema definitions. Collections can hold any type adhering to KvValue.

Note: Index values are always serialized, using the JSON-encoder by default, or alternatively your provided encoder.

Collection Options

These are all the options available for the collection() method, used when defining collections of documents. All collection options are optional.

idGenerator

Override the default id generator, which is used to automatically generate an id when adding a new document. The id generatror gets called with the data being added, which can be useful to create derived ids. The default id generator uses ulid() from Deno's standard library.

Id created from the data being added:

import { collection, kvdex, model } from "@olli/kvdex";

const kv = await Deno.openKv();

const db = kvdex({
  kv: kv,
  schema: {
    users: collection(model<User>(), {
      idGenerator: (user) => user.username,
    }),
  },
});

Using randomely generated uuids:

import { collection, kvdex, model } from "@olli/kvdex";

const kv = await Deno.openKv();

const db = kvdex({
  kv: kv,
  schema: {
    users: collection(model<User>(), {
      idGenerator: () => crypto.randomUUID(),
    }),
  },
});

indices

Define indices for collections of objects. Used to optimize operations by querying data based on index values.

NOTE: Index values are always serialized.

import { collection, kvdex, model } from "@olli/kvdex";

const kv = await Deno.openKv();

const db = kvdex({
  kv: kv,
  schema: {
    users: collection(model<User>(), {
      indices: {
        username: "primary", // unique
        age: "secondary", // non-unique
      },
    }),
  },
});

encoder

Specify serialization and compression for the collection. This lets large objects that exceed the native size limit of 64kb to be stored, by serializing, compressing and dividing the value across multiple key/value entries. When an encoder is specified, there is a tradeoff between speed and storage efficiency. For storing objects larger than the atomic operation size limit, see Blob Storage.

import { kvdex, collection, model } from "@olli/kvdex"
import { jsonEncoder } from "@olli/kvdex/encoding/json"
import { v8Encoder } from "@olli/kvdex/encoding/v8"
import { brotliCompression } from "@olli/kvdex/encoding/brotli"

const kv = await Deno.openKv()

const db = kvdex({
  kv: kv,
  schema: {
    users: collection(model<User>(), {
        // JSON-encoder without compression (best runtime compatibility)
        encoder: jsonEncoder(),

        // JSON-encoder + Brotli compression (requires node:zlib built-in)
        encoder: jsonEncoder({ compression: brotliCompression() }),

        // V8-encoder without brotli compression (requires node:v8 built-in)
        encoder: v8Encoder()

        // V8-encoder + brotli compression (requires node:v8 and node:zlib built-in)
        encoder: v8Encoder({ compression: brotliCompression() })

        // Set custom serialize, deserialize, compress and decompress functions
        encoder: {
          serializer: {
            serialize: ...,
            deserialize: ...,
          },
          // optional
          compressor: {
            compress: ...,
            decompress: ...,
          }
        }
      }),
  }
})

history

Set to true to enable version history. Default is false.

import { collection, kvdex, model } from "@olli/kvdex";

const kv = await Deno.openKv();

const db = kvdex({
  kv: kv,
  schema: {
    users: collection(model<User>(), {
      history: true,
    }),
  },
});

Collection Methods

find()

Retrieve a single document with the given id from the KV store. The id must adhere to the type KvId. This method takes an optional options argument that can be used to set the consistency mode.

const userDoc1 = await db.users.find(123);

const userDoc2 = await db.users.find(123n);

const userDoc3 = await db.users.find("oliver", {
  consistency: "eventual", // "strong" by default
});

findByPrimaryIndex()

Find a document by a primary index.

// Finds a user document with the username = "oliver"
const userByUsername = await db.users.findByPrimaryIndex("username", "oliver");

findBySecondaryIndex()

Find documents by a secondary index. Secondary indices are not unique, and therefore the result is an array of documents. The method takes an optional options argument that can be used for filtering of documents, and pagination.

// Returns all users with age = 24
const { result } = await db.users.findBySecondaryIndex("age", 24);

// Returns all users with age = 24 AND username that starts with "o"
const { result } = await db.users.findBySecondaryIndex("age", 24, {
  filter: (doc) => doc.value.username.startsWith("o"),
});

findMany()

Retrieve multiple documents with the given array of ids from the KV store. The ids must adhere to the type KvId. This method takes an optional options argument that can be used to set the consistency mode.

const userDocs1 = await db.users.findMany(["abc", 123, 123n]);

const userDocs2 = await db.users.findMany(["abc", 123, 123n], {
  consistency: "eventual", // "strong" by default
});

findHistory()

Retrieve the version history of a document by id. A history entry contains a timestamp, type of either "write" or "delete", and a copy of the document value if the type is "write".

const { result } = await db.users.findHistory("user_id");

const { result } = await db.users.findHistory("user_id", {
  filter: (entry) => entry.type === "write",
});

findUndelivered()

Retrieve a document entry that was not delivered during an enqueue() operation in the collection queue. This method takes an optional options argument that can be used to set the consistency mode.

const doc1 = await db.users.findUndelivered("undelivered_id");

const doc2 = await db.users.findUndelivered("undelivered_id", {
  consistency: "eventual", // "strong" by default
});

add()

Add a new document to the KV store with an auto-generated id (ulid by default). Upon completion, a CommitResult object will be returned with the document id, versionstamp and ok flag.

const result = await db.users.add({
  username: "oliver",
  age: 24,
  activities: ["skiing", "running"],
  address: {
    country: "Norway",
    city: "Bergen",
    street: "Sesame",
    houseNumber: null,
  },
});

addMany()

Add multiple document entries to the KV store with auto-generated ids (ulid by default). Upon completion, a list of CommitResult objects will be returned.

// Adds 5 new document entries to the KV store.
await result = await db.numbers.addMany([1, 2, 3, 4, 5])

// Only adds the first entry, as "username" is defined as a primary index and cannot have duplicates
await result = await db.users.addMany([
  {
    username: "oli",
    age: 24
  },
  {
    username: "oli",
    age: 56
  }
])

set()

Set a document entry in the KV store with a given id of type KvId. Upon completion, a CommitResult object will be returned with the document id, versionstamp and ok flag.

// Add a new document if the id is not already in use
const result1 = await db.numbers.set("id", 1024);

// Overwrite any existing document with the same id
const result2 = await db.numbers.set("id", 2048, { overwrite: true });

if (result1.ok) {
  console.log(result.id); // id
}

update()

Updates the value of an exisiting document in the KV store by id. By default, the merge strategy is used when available, falling back to replace for primitive types and built-in objects (Date, RegExp, etc.). For plain objects, the merge-shallow strategy is also supported.

// Updates the document with a new value
const result = await db.numbers.update("num1", 42);

// Partial update using merge, only updates the age field
const result = await db.users.update(
  "oliver",
  { age: 30 },
  { strategy: "merge" },
);

updateByPrimaryIndex()

Update a document by a primary index.

// Updates a user with username = "oliver" to have age = 56
const result = await db.users.updateByPrimaryIndex(
  "username",
  "oliver",
  { age: 56 },
);

// Updates a user document using shallow merge
const result = await db.users.updateByPrimaryIndex(
  "username",
  "anders",
  { age: 89 },
  { strategy: "merge-shallow" },
);

updateBySecondaryIndex()

Update documents by a secondary index. Takes an optional options argument that can be used for filtering of documents to be updated, and pagination. If no options are given, all documents by the given index value will we updated.

// Updates all user documents with age = 24 and sets age = 67
const { result } = await db.users.updateBySecondaryIndex("age", 24, {
  age: 67,
});

// Updates all users where age = 24 and username starts with "o", using shallow merge
const { result } = await db.users.updateBySecondaryIndex(
  "age",
  24,
  { age: 67 },
  {
    filter: (doc) => doc.value.username.startsWith("o"),
    strategy: "merge-shallow",
  },
);

updateMany()

Update the value of multiple existing documents in the KV store. It takes an optional options argument that can be used for filtering of documents to be updated, and pagination. If no options are given, "updateMany" will update all documents in the collection.

// Updates all user documents and sets age = 67
const { result } = await db.users.updateMany({ age: 67 });

// Updates all users where age > 20, using shallow merge
const { result } = await db.users.updateMany({ age: 67 }, {
  filter: (doc) => doc.value.age > 20,
  strategy: "merge-shallow",
});

// Only updates first user document and fails the rest when username is a primary index
const { result } = await db.users.updateMany({ username: "oliver" });

updateManyBySecondaryOrder()

Update the value of multiple existing documents in the collection by a secondary order.

// Updates the first 10 users ordered by age and sets username = "anon"
await db.users.updateManyBySecondaryOrder("age", { username: "anon" });

updateOne()

Update the first matching document from the KV store. It optionally takes the same options argument as updateMany(). If no options are given, updateOne() will update the first document in the collection.

// Updates the first user document and sets age = 67
const result = await db.users.updateOne({ age: 67 });

// Updates the first user where age > 20, using shallow merge
const result = await db.users.updateOne({ age: 67 }, {
  filter: (doc) => doc.value.age > 20,
  strategy: "merge-shallow",
});

updateOneBySecondaryIndex()

Update the first matching document from the KV store by a secondary index. It optionally takes the same options argument as updateMany(). If no options are given, updateOneBySecondaryIndex() will update the first document in the collection by the given index value.

// Updates the first user document where age = 20 and sets age = 67
const result = await db.users.updateOneBySecondaryIndex("age", 20, { age: 67 });

// Updates the first user where age = 20 and username starts with "a", using shallow merge
const result = await db.users.updateOneBySecondaryIndex(
  "age",
  20,
  { age: 67 },
  {
    filter: (doc) => doc.value.username.startsWith("a"),
    strategy: "merge-shallow",
  },
);

updateOneBySecondaryOrder()

Update the value of one existing document in the collection by a secondary order.

// Updates the first user ordered by age and sets username = "anon"
const result = await db.users.updateOneBySecondaryOrder("age", {
  username: "anon",
});

upsert()

Update an existing document by id, or set a new document entry if no matching document exists.

const result = await db.users.upsert({
  id: "user_id",
  update: { username: "Chris" },
  set: {
    username: "Chris",
    age: 54,
    activities: ["bowling"],
    address: {
      country: "USA",
      city: "Las Vegas"
      street: "St. Boulevard"
      houseNumber: 23
    }
  }
})

upsertByPrimaryIndex()

Update an existing document by a primary index, or set a new entry if no matching document exists. An id can be optionally specified which will be used when creating a new document entry.

const result = await db.users.upsertByPrimaryIndex({
  index: ["username", "Jack"],
  update: { username: "Chris" },
  set: {
    username: "Chris",
    age: 54,
    activities: ["bowling"],
    address: {
      country: "USA",
      city: "Las Vegas"
      street: "St. Boulevard"
      houseNumber: 23
    }
  }
})

delete()

Delete one or more documents with the given ids from the KV store.

await db.users.delete("f897e3cf-bd6d-44ac-8c36-d7ab97a82d77");

await db.users.delete("user1", "user2", "user3");

deleteByPrimaryIndex()

Delete a document by a primary index.

// Deletes user with username = "oliver"
await db.users.deleteByPrimaryIndex("username", "oliver");

deleteBySecondaryIndex()

Delete documents by a secondary index. The method takes an optional options argument that can be used for filtering of documents, and pagination.

// Deletes all users with age = 24
await db.users.deleteBySecondaryIndex("age", 24);

// Deletes all users with age = 24 AND username that starts with "o"
await db.users.deleteBySecondaryIndex("age", 24, {
  filter: (doc) => doc.value.username.startsWith("o"),
});

deleteMany()

Delete multiple documents from the KV store without specifying ids. It takes an optional options argument that can be used for filtering of documents to be deleted, and pagination. If no options are given, "deleteMany" will delete all documents in the collection.

// Deletes all user documents
await db.users.deleteMany();

// Deletes all user documents where the user's age is above 20
await db.users.deleteMany({
  filter: (doc) => doc.value.age > 20,
});

// Deletes the first 10 user documents in the KV store
await db.users.deleteMany({
  limit: 10,
});

// Deletes the last 10 user documents in the KV store
await db.users.deleteMany({
  limit: 10,
  reverse: true,
});

deleteManyBySecondaryOrder()

Delete multiple documents from the KV store by a secondary order. The method takes an optional options argument that can be used for filtering of documents, and pagination. If no options are provided, all documents in the collection are deleted.

// Deletes the first 10 users ordered by age
await db.users.deleteManyBySecondaryOrder("age", { limit: 10 });

deleteHistory()

Delete the version history of a document by id.

await db.users.deleteHistory("user_id");

deleteUndelivered()

Delete an undelivered document entry by id from the collection queue.

await db.users.deleteUndelivered("id");

getMany()

Retrieve multiple documents from the KV store. It takes an optional options argument that can be used for filtering of documents to be retrieved, and pagination. If no options are given, getMany() will retrieve all documents in the collection.

// Retrieves all user documents
const { result } = await db.users.getMany();

// Retrieves all user documents where the user's age is above or equal to 18
const { result } = await db.users.getMany({
  filter: (doc) => doc.value.age >= 18,
});

// Retrieves the first 10 user documents in the KV store
const { result } = await db.users.getMany({
  limit: 10,
});

// Retrieves the last 10 user documents in the KV store
const { result } = await db.users.getMany({
  limit: 10,
  reverse: true,
});

getManyBySecondaryOrder()

Retrieves multiple documents from the KV store in the specified secondary order and according to the given options. If no options are provided, all documents are retrieved.

// Get all users ordered by age
const { result } = await db.users.getManyBySecondaryOrder("age");

// Only get users with username that starts with "a", ordered by age
const { result } = await db.users.getManyBySecondaryOrder("age", {
  filter: (doc) => doc.value.username.startsWith("a"),
});

getOne()

Retrieve the first matching document from the KV store. It optionally takes the same options argument as getMany(). If no options are given, getOne() will retrieve the first document in the collection.

// Retrieves the first user document
const user = await db.users.getOne();

// Retrieves the first user where the user's age is above or equal to 18
const user = await db.users.getOne({
  filter: (doc) => doc.value.age > 18,
});

getOneBySecondaryIndex()

Retrieve the first matching document from the KV store by a secondary index. It optionally takes the same options argument as getMany(). If no options are given, getOneBySecondaryIndex() will retrieve the first document in the collection by the given index value.

// Retrieves the first user document where age = 20
const user = await db.users.getOneBySecondaryIndex("age", 20);

// Retrieves the first user where age = 20 and username starts with "a"
const user = await db.users.getOneBySecondaryIndex("age", 20, {
  filter: (doc) => doc.value.username.startsWith("a"),
});

getOneBySecondaryOrder()

Retrieves one document from the KV store by a secondary order and according to the given options. If no options are provided, the first document in the collection by the given order is retrieved.

// Get the first user ordered by age
const user = await db.users.getOneBySecondaryOrder("age");

forEach()

Execute a callback function for multiple documents in the KV store. Takes an optional options argument that can be used for filtering of documents and pagination. If no options are given, the callback function will be executed for all documents in the collection.

// Log the username of every user document
await db.users.forEach((doc) => console.log(doc.value.username));

// Log the username of every user that has "swimming" as an activity
await db.users.forEach((doc) => console.log(doc.value.username), {
  filter: (doc) => doc.value.activities.includes("swimming"),
});

// Log the usernames of the first 10 user documents in the KV store
await db.users.forEach((doc) => console.log(doc.value.username), {
  limit: 10,
});

// Log the usernames of the last 10 user documents in the KV store
await db.users.forEach((doc) => console.log(doc.value.username), {
  limit: 10,
  reverse: true,
});

forEachBySecondaryIndex()

Execute a callback function for documents by a secondary index. Takes an optional options argument that can be used for filtering of documents and pagination. If no options are given, the callback function will be executed for all documents in the collection matching the index.

// Prints the username of all users where age = 20
await db.users.forEachBySecondaryIndex(
  "age",
  20,
  (doc) => console.log(doc.value.username),
);

forEachBySecondaryOrder()

Executes a callback function for every document by a secondary order and according to the given options. If no options are provided, the callback function is executed for all documents.

// Prints the username of all users ordered by age
await db.users.forEachBySecondaryOrder(
  "age",
  (doc) => console.log(doc.value.username),
);

map()

Execute a callback function for multiple documents in the KV store and retrieve the results. It takes an optional options argument that can be used for filtering of documents and pagination. If no options are given, the callback function will be executed for all documents in the collection.

// Get a list of all the ids of the user documents
const { result } = await db.users.map((doc) => doc.id);

// Get a list of all usernames of users with age > 20
const { result } = await db.users.map((doc) => doc.value.username, {
  filter: (doc) => doc.value.age > 20,
});

// Get a list of the usernames of the first 10 users in the KV store
const { result } = await db.users.map((doc) => doc.value.username, {
  limit: 10,
});

// Get a list of the usernames of the last 10 users in the KV store
const { result } = await db.users.map((doc) => doc.value.username, {
  limit: 10,
  reverse: true,
});

mapBySecondaryIndex()

Executes a callback function for documents by a secondary index and retrieves the results. It takes an optional options argument that can be used for filtering of documents and pagination. If no options are given, the callback function will be executed for all documents matching the index.

// Returns a list of usernames of all users where age = 20
const { result } = await db.users.mapBySecondaryIndex(
  "age",
  20,
  (doc) => doc.value.username,
);

mapBySecondaryOrder()

Executes a callback function for every document by a secondary order and according to the given options. If no options are provided, the callback function is executed for all documents. The results from the callback function are returned as a list.

// Returns a list of usernames of all users ordered by age
const { result } = await db.users.mapBySecondaryOrder(
  "age",
  (doc) => doc.value.username,
);

count()

Count the number of documents in a collection. Takes an optional options argument that can be used for filtering of documents. If no options are given, it will count all documents in the collection.

// Returns the total number of user documents in the KV store
const count = await db.users.count();

// Returns the number of users with age > 20
const count = await db.users.count({
  filter: (doc) => doc.value.age > 20,
});

countBySecondaryIndex()

Counts the number of documents in the collection by a secondary index. Takes an optional options argument that can be used for filtering of documents. If no options are given, it will count all documents matching the index.

// Counts all users where age = 20
const count = await db.users.countBySecondaryIndex("age", 20);

countBySecondaryOrder()

Counts the number of documents in the collection by a secondary order.

// Counts how many of the first 10 users ordered by age that are under the age of 18
const count = await db.users.countBySecondaryOrder("age", {
  limit: 10,
  filter: (doc) => doc.value.age < 18,
});

enqueue()

Add data to the collection queue to be delivered to the queue listener via db.collection.listenQueue(). The data will only be received by queue listeners on the specified collection and topic. The method takes an optional options argument that can be used to set a delivery delay and topic.

// Immediate delivery
await db.users.enqueue("some data");

// Delay of 2 seconds before delivery
await db.users.enqueue("cake", {
  delay: 2_000,
  topic: "food",
});

listenQueue()

Listen for data from the collection queue that was enqueued with db.collection.enqueue(). Will only receive data that was enqueued to the specific collection queue and topic. Expects a handler function as argument, as well as optional options that can be used to set the topic.

// Prints the data to console when recevied
db.users.listenQueue((data) => console.log(data));

// Sends post request when data is received
db.users.listenQueue(async (data) => {
  const dataBody = JSON.stringify(data);

  const res = await fetch("...", {
    method: "POST",
    body: data,
  });

  console.log("POSTED:", dataBody, res.ok);
}, { topic: "posts" });

watch()

Listen for live changes to a single document by id.

// Updates the document value every second
setInterval(() => db.numbers.set("id", Math.random()), 1_000);

// Listen for any updates to the document value
db.numbers.watch("id", (doc) => {
  // Document will be null if the latest update was a delete operation
  console.log(doc?.value);
});

Watchers can also be stopped.

const { promise, cancel } = db.numbers.watch("id", (doc) => {
  // ...
});

await cancel();
await promise;

watchMany()

Listen for live changes to an array of specified documents by id.

// Delayed setting of document values
setTimeout(() => db.numbers.set("id1", 10), 1_000);
setTimeout(() => db.numbers.set("id2", 20), 2_000);
setTimeout(() => db.numbers.set("id3", 30), 3_000);

// Listen for any updates to the document values
db.numbers.watchMany(["id1", "id2", "id3"], (docs) => {
  // Prints for each update to any of the documents
  console.log(docs[0]?.value); // 10, 10, 10
  console.log(docs[1]?.value); // null, 20, 20
  console.log(docs[2]?.value); // null, null, 30
});

Watchers can also be stopped.

const { promise, cancel } = db.numbers.watchMany(
  ["id1", "id2", "id3"],
  (docs) => {
    // ...
  },
);

await cancel();
await promise;

Database Methods

These are methods which can be found at the top level of your database object, and perform operations across multiple collections or unrelated to collections.

countAll()

Count the total number of documents across all collections. It takes an optional options argument that can be used to set the consistency mode.

// Gets the total number of documents in the KV store across all collections
const count = await db.countAll();

deleteAll()

Delete all documents across all collections.

await db.deleteAll();

wipe()

Delete all kvdex entries, including undelivered and history entries.

await db.wipe();

deleteUndelivered()

Delete an undelivered document entry by id from the database queue.

await db.deleteUndelivered("id");

findUndelivered()

Retrieve a document entry that was not delivered during an enqueue() operation in the database queue. This method takes an optional options argument that can be used to set the consistency mode.

const doc1 = await db.findUndelivered("undelivered_id");

const doc2 = await db.findUndelivered("undelivered_id", {
  consistency: "eventual", // "strong" by default
});

enqueue()

Add data to the database queue to be delivered to the queue listener via db.listenQueue(). The data will only be received by queue listeners on the database queue and specified topic. The method takes an optional options argument that can be used to set a delivery delay and topic.

// Immediate delivery
await db.enqueue("some data");

// Delay of 2 seconds before delivery
await db.enqueue("cake", {
  delay: 2_000,
  topic: "food",
});

listenQueue()

Listen for data from the database queue that was enqueued with db.enqueue(). Will only receive data that was enqueued to the database queue and specified topic. Expects a handler function as argument, as well as optional options that can be used to set the topic.

// Prints the data to console when recevied
db.listenQueue((data) => console.log(data));

// Sends post request when data is received in the "posts" topic
db.listenQueue(async (data) => {
  const dataBody = JSON.stringify(data);

  const res = await fetch("...", {
    method: "POST",
    body: data,
  });

  console.log("POSTED:", dataBody, res.ok);
}, { topic: "posts" });

setInterval()

Create an interval built on queues that can run indefinitely or as long as a while condition is met. Interval time is given in milliseconds, and can be set by either a static number or dynamically by a function. There is an enforced minimum start delay of 1 second to ensure the queue listener is registered before the first delivery.

// Will repeat indefinitely with 1 second interval
db.setInterval(() => console.log("Hello World!"), 1_000);

// First callback starts after a 10 second delay, after that there is a random interval between 0 and 5 seconds
db.setInterval(
  () => console.log("I terminate after running 10 times"),
  () => Math.random() * 5_000,
  {
    // Delay before the first callback is invoked
    startDelay: 10_000,

    // Count starts at 0 and is given before the current callback is run
    while: ({ count }) => count < 10,
  },
);

loop()

Create a loop built on queues that can run indefinitely or as long as a while condition is met. In contrast to setInterval(), the callback function in a loop is run sequentially, meaning the next callback is not enqueued until the previous task finishes. There is an enforced minimum start delay of 1 second to ensure the queue listener is registered before the first delivery.

// Sequentially prints "Hello World!" indefinitely with no delay between each iteration
db.loop(() => console.log("Hello World!"));

// Sequentially prints "Hello World!" 10 times, with a 3 second delay between each iteration
db.loop(() => console.log("Hello World!"), {
  delay: 3_000,
  while: ({ count }) => count < 10,
});

atomic()

Initiate an atomic operation. The method takes a selector function as argument for selecting the initial collection context.

db.atomic((schema) => schema.users);

Atomic Operations

Atomic operations allow for executing multiple mutations as a single atomic transaction. This means that documents can be checked for changes before committing the mutations, in which case the operation will fail. It also ensures that either all mutations succeed, or they all fail.

To initiate an atomic operation, call "atomic" on the database object. The method expects a selector for selecting the collection that the subsequent mutation actions will be performed on. Mutations can be performed on documents from multiple collections in a single atomic operation by calling "select" at any point in the building chain to switch the collection context. To execute the operation, call "commit" at the end of the chain. A committed atomic operation returns a promise resolving to either a Deno.KvCommitResult object if successful, or Deno.KvCommitError if not.

NOTE: Atomic operations are not available for serialized collections. For indexable collections, any operations performing deletes will not be truly atomic in the sense that it performs a single isolated operation. This is because the document data must be read before performing the initial delete operation, to then perform another delete operation for the index entries. If the initial operation fails, the index entries will not be deleted. To avoid collisions and errors related to indexing, an atomic operation will always fail if it is trying to delete and write to the same indexable collection. It will also fail if trying to set/add a document with colliding index entries, or if trying to set a document with the overwrite option.

Without checking

// Deletes and adds an entry to the numbers collection
const result1 = await db
  .atomic((schema) => schema.numbers)
  .delete("id_1")
  .set("id_2", 100)
  .commit();

// Adds 2 new entries to the numbers collection and 1 new entry to the users collection
const result2 = await db
  .atomic((schema) => schema.numbers)
  .add(1)
  .add(2)
  .select((schema) => schema.users)
  .set("user_1", {
    username: "oliver",
    age: 24,
    activities: ["skiing", "running"],
    address: {
      country: "Norway",
      city: "Bergen",
      street: "Sesame",
      houseNumber: 42,
    },
  })
  .commit();

// Will fail and return Deno.KvCommitError because it is trying
// to both add and delete from an indexable collection
const result3 = await db
  .atomic((schema) => schema.users)
  .delete("user_1")
  .set("user_1", {
    username: "oliver",
    age: 24,
    activities: ["skiing", "running"],
    address: {
      country: "Norway",
      city: "Bergen",
      street: "Sesame",
      houseNumber: 42,
    },
  })
  .commit();

With checking

// Only adds 10 to the value when it has not been changed since being read
let result = null;
while (!result || !result.ok) {
  const { id, versionstamp, value } = await db.numbers.find("id");

  result = await db
    .atomic((schema) => schema.numbers)
    .check({
      id,
      versionstamp,
    })
    .set(id, value + 10)
    .commit();
}

Document Methods

These are methods on the Document object which perform actions/mutations on the document contents.

flat()

Flatten top layer of document data. Returns an object containing the id, versionstamp and value entries for documents of type Model, else simply returns the document data.

// We assume the document exists in the KV store
const doc = await db.users.find(123n);
const flattened = doc.flat();

// Document:
// {
//   id,
//   versionstamp,
//   value
// }

// Flattened:
// {
//   id,
//   versionstamp,
//   ...value
// }

Extensions

Additional features outside of the basic functionality provided by kvdex. While the core functionalities are free of third-party dependencies, extended features may rely on third-party dependenices or runtime-specific APIs to enhance integration.

Encoding

Utilities for encoding data.

JSON

JSON-encoder and utilities for stringifying and serializing data.

import { jsonEncoder } from "@olli/kvdex/encoding/json";

// With default options (no compression)
const encoder = jsonEncoder();

import { jsonEncoder } from "@olli/kvdex/encoding/json";
import { brotliCompressor } from "@olli/kvdex/encoding/brotli";

// With brotli compression
const encoder = jsonEncoder({ compressor: brotliCompressor() });

import { jsonParse, jsonStringify } from "@olli/kvdex/encoding/json";

// Stringify value
const json = jsonStringify({
  foo: "bar",
  big: 100n,
});

// Parse value
const value = jsonParse(json);

import { jsonDeserialize, jsonSerialize } from "@olli/kvdex/encoding/json";

// Serialize value as Uint8Array
const serialized = jsonSerialize({
  foo: "bar",
  big: 100n,
});

// Deserialize value from Uint8Array
const value = jsonDeserialize(serialized);

V8

V8-encoder and serialization utilities. Relies on the node:v8 built-in.

import { v8Encoder } from "@olli/kvdex/encoding/v8";
import { brotliCompressor } from "@olli/kvdex/encoding/brotli";

// V8-encoder without compression
const encoder = v8Encoder();

// V8-encoder with brotli compression
const encoder = v8Encoder({ compressor: brotliCompressor() });

import { v8Deserialize, v8Serialize } from "@olli/kvdex/encoding/v8";

// Serialize value as Uint8Array
const serialized = v8Serialize({
  foo: "bar",
  big: 100n,
});

// Deserialize value from Uint8Array
const value = v8Deserialize(serialized);

Brotli

Easy to configure brotli compression for use with the encoder option for collections. Relies on the node:zlib built-in.

import { brotliCompressor } from "@olli/kvdex/encoding/brotli";

// With default options
const compressor = brotliCompressor();

// Explicitly set quality level (default is 1)
const compressor = brotliCompressor({ quality: 2 });

Zod

Extended support for Zod. Includes schemas for some of the KV-types.

Schemas

The zod extension provides schemas for some of the KV-types, such as KvId, KvValue, KvObject and KvArray. This makes it easier to properly build your schemas.

import { z } from "npm:zod";
import { KvIdSchema } from "@olli/kvdex/zod";

const UserSchema = z.object({
  username: z.string(),
  postIds: z.array(KvIdSchema),
});

const PostSchema = z.object({
  text: z.string(),
  userId: KvIdSchema,
});

Migrate

A helper script and function for migrating entries from a source KV instance to a target KV instance. Only migrates kvdex entries by default, but optionally allows for migrating all entries.

Script

Run the migrate script and provide --source and --target arguments. Optionally pass --all to migrate all entries.

deno run -A --unstable-kv jsr:@olli/kvdex/migrate --source=./source.sqlite3 --target=./target.sqlite3

Function

Use the migrate function and pass a source KV instance and a target KV instance. Optionally pass all: true to migrate all entries.

import { migrate } from "@olli/kvdex/migrate";

const source = await Deno.openKv("./source.sqlite3");
const target = await Deno.openKv("./target.sqlite3");

await migrate({
  source,
  target,
});

KV

Support for alternative KV backends, such as Map and localStorage. Can be used to employ kvdex in the browser or other environments where Deno's KV store is not available, or to adapt to other database backends.

import { kvdex } from "@olli/kvdex";
import { MapKv } from "@olli/kvdex/kv";

// Create a database from a `MapKv` instance, using `Map` as it's backend by default.
const kv = new MapKv(); // Equivalent to `new MapKv({ map: new Map() })`
const db = kvdex({ kv });

import { kvdex } from "@olli/kvdex";
import { MapKv, StorageAdapter } from "@olli/kvdex/kv";

// Create a temporary database from a `MapKv` instance,
// explicitly using `localStorage` as it's backend.
const map = new StorageAdapter(localStorage);
const kv = new MapKv({ map, clearOnClose: true });
const db = kvdex({ kv });

Blob Storage

To store large blob sizes, and bypass the data limit of a single atomic operation, a combination of serialized collections and batched atomic operations can be used. By default, batching is disabled to ensure consistency and improve performance.

import { collection, kvdex, model } from "@olli/kvdex"
import { jsonEncoder } from "@olli/kvdex/encoding/json"

const kv = await Deno.openKv()
const db = kvdex({
  kv: kv,
  schema: {
    blobs: collection(model<Uint8Array>(), { encoder: jsonEncoder() }),
  }
})

const blob = // read from disk, etc.

const result = await db.blobs.add(blob, { batched: true })

Development

Any contributions are welcomed and appreciated. How to contribute:

• Clone this repository
• Add feature / Refactor
• Add or refactor tests as needed
• Ensure code quality (check + lint + format + test) using deno task prep
• Open Pull Request

This project aims at having as high test coverage as possible to improve code quality and to avoid breaking features when refactoring. Therefore it is encouraged that any feature contributions are also accompanied by relevant unit tests to ensure those features remain stable.

The goal of kvdex is to provide a type safe, higher-level API to Deno KV, while retaining as much of the native functionality as possible. Additionally, the core functionality (excluding extensions) should not rely on any third-party dependencies. Please kleep this in mind when making any contributions.

License

Published under MIT License