# respite

> _respite_
> An interruption in the intensity or amount of something.

This project is a way to disrupt the stress. It is also an in-memory key/value
store.

## At a Glance

- Single instance (no clustered mode)
- Concurrency support and atomic operations
- No Schema
- No Pub/Sub
- Supports specific types
- Supports key and value constraints
- HTTP API

### Supported Key Types

The sizes below omit the size of heap references (64 bits).

| Type     | Size in Bytes | Description            |
| -------- | ------------- | ---------------------- |
| `int64`  | `8`           | Signed 64-bit integer. |
| `string` | Variable      | UTF-16                 |
| `uuid`   | `16`          | N/A                    |
| `date`   | `8`           | Year, month, day.      |

### Supported Value Types

The sizes below omit the size of heap references (64 bits). Booleans do not have
precisely defined sizes on the JVM, but 1 byte is typical.

| Type     | Size in Bytes | Description            |
| -------- | ------------- | ---------------------- |
| `int64`  | `8`           | Signed 64-bit integer. |
| `string` | Variable      | UTF-16                 |
| `uuid`   | `16`          | N/A                    |
| `date`   | `8`           | Year, month, day.      |
| `bool`   | `1`           | True/false.            |
| `byte`   | Variable      | Any byte array.        |

### Supported Operations

- Get
- Set
- Delete
- Increment
- Decrement
- Compare and Swap
- Insert
- Contains

### Supported Constraints

Any of the following constraints may be applied to a single key space. If any
operation on the key space violates a constraint, that operation fails.

| Constraint          | Description                                                                |
| ------------------- | -------------------------------------------------------------------------- |
| `single_key_type`   | Only the given type is accepted for keys.                                  |
| `single_value_type` | Only the given type is accepted for values.                                |
| `write_once`        | Each key may be written exactly once. Deletes and reassignments will fail. |

## HTTP API

Respite provides an HTTP API that uses JSON to transmit data.