fix already closed error (#29)

* fix already closed error

* remove fatal errors

* add CoC + readme

* add array support

* add array support

Author: tanner0101

CODE_OF_CONDUCT.md

@@ -0,0 +1,59 @@
+# Code of Conduct
+
+To be a truly great community, Swift.org needs to welcome developers from all walks of life,
+with different backgrounds, and with a wide range of experience. A diverse and friendly
+community will have more great ideas, more unique perspectives, and produce more great 
+code. We will work diligently to make the Swift community welcoming to everyone.
+
+To give clarity of what is expected of our members, Swift.org has adopted the code of conduct 
+defined by [contributor-covenant.org](https://www.contributor-covenant.org). This document is used across many open source 
+communities, and we think it articulates our values well. The full text is copied below:
+
+### Contributor Code of Conduct v1.3
+
+As contributors and maintainers of this project, and in the interest of fostering an open and 
+welcoming community, we pledge to respect all people who contribute through reporting 
+issues, posting feature requests, updating documentation, submitting pull requests or patches, 
+and other activities.
+
+We are committed to making participation in this project a harassment-free experience for 
+everyone, regardless of level of experience, gender, gender identity and expression, sexual 
+orientation, disability, personal appearance, body size, race, ethnicity, age, religion, or 
+nationality.
+
+Examples of unacceptable behavior by participants include:
+
+- The use of sexualized language or imagery
+- Personal attacks
+- Trolling or insulting/derogatory comments
+- Public or private harassment
+- Publishing other’s private information, such as physical or electronic addresses, without explicit permission
+- Other unethical or unprofessional conduct
+
+Project maintainers have the right and responsibility to remove, edit, or reject comments, 
+commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of 
+Conduct, or to ban temporarily or permanently any contributor for other behaviors that they 
+deem inappropriate, threatening, offensive, or harmful.
+
+By adopting this Code of Conduct, project maintainers commit themselves to fairly and 
+consistently applying these principles to every aspect of managing this project. Project 
+maintainers who do not follow or enforce the Code of Conduct may be permanently removed 
+from the project team.
+
+This code of conduct applies both within project spaces and in public spaces when an 
+individual is representing the project or its community.
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by 
+contacting a project maintainer at [[email protected]](mailto:[email protected]). All complaints will be reviewed and 
+investigated and will result in a response that is deemed necessary and appropriate to the 
+circumstances. Maintainers are obligated to maintain confidentiality with regard to the reporter 
+of an incident.
+
+*This policy is adapted from the Contributor Code of Conduct [version 1.3.0](http://contributor-covenant.org/version/1/3/0/).*
+
+### Reporting
+
+A working group of community members is committed to promptly addressing any [reported 
+issues](mailto:[email protected]). Working group members are volunteers appointed by the project lead, with a 
+preference for individuals with varied backgrounds and perspectives. Membership is expected 
+to change regularly, and may grow or shrink.

README.md

@@ -1,3 +1,189 @@
 # NIOPostgres 
 
-🐘 Non-blocking, event-driven Swift client for PostgreSQL.
+🐘 Non-blocking, event-driven Swift client for PostgreSQL built on [SwiftNIO](https://github.com/apple/swift-nio).
+
+### Major Releases
+
+The table below shows a list of NIOPostgres major releases alongside their compatible NIO and Swift versions. 
+
+Version | NIO | Swift | SPM
+--- | --- | --- | ---
+1.0 (alpha) | 2.0+ | 5.0+ | `from: "1.0.0-alpha"`
+
+Use the SPM string to easily include the dependendency in your `Package.swift` file.
+
+```swift
+.package(url: "https://github.com/vapor/nio-postgres.git", from: ...)
+```
+
+### Supported Platforms
+
+NIOPostgres supports the following platforms:
+
+- Ubuntu 14.04+
+- macOS 10.12+
+
+## Overview
+
+NIOPostgres is a client package for connecting to, authorizing, and querying a PostgreSQL server. At the heart of this module are NIO channel handlers for parsing and serializing messages in PostgreSQL's proprietary wire protocol. These channel handlers are combined in a request / response style connection type that provides a convenient, client-like interface for performing queries. 
+
+Support for both simple (text) and parameterized (binary) querying is provided out of the box alongside a `PostgresData` type that handles conversion between PostgreSQL's wire format and native Swift types.
+
+### Motiviation
+
+Most Swift implementations of Postgres clients are based on the [libpq](https://www.postgresql.org/docs/11/libpq.html) C library which handles transport internally. Building a library directly on top of Postgres' wire protocol using SwiftNIO should yield a more reliable, maintainable, and performant interface for PostgreSQL databases.
+
+### Goals
+
+This package is meant to be a low-level, unopinionated PostgreSQL wire-protocol implementation for Swift. The hope is that higher level packages can share NIOPostgres as a foundation for interacting with PostgreSQL servers without needing to duplicate complex logic.
+
+Because of this, NIOPostgres excludes some important concepts for the sake of simplicity, such as:
+
+- Connection pooling
+- Swift `Codable` integration
+- Query building
+
+If you are looking for a PostgreSQL client package to use in your project, take a look at these higher-level packages built on top of NIOPostgres:
+
+- [`vapor/postgres-kit`](https://github.com/vapor/postgresql)
+
+### Dependencies
+
+This package has four dependencies:
+
+- [`apple/swift-nio`](https://github.com/apple/swift-nio) for IO
+- [`apple/swift-nio-ssl`](https://github.com/apple/swift-nio-ssl) for TLS
+- [`apple/swift-log`](https://github.com/apple/swift-logs) for logging
+- [`apple/swift-metrics`](https://github.com/apple/swift-metrics) for metrics
+
+This package has no additional system dependencies.
+
+## API Docs
+
+Check out the [NIOPostgres API docs]((https://api.vapor.codes/nio-postgres/master/NIOPostgres/index.html)) for a detailed look at all of the classes, structs, protocols, and more.
+
+## Getting Started
+
+This section will provide a quick look at using NIOPostgres.
+
+### Creating a Connection
+
+The first step to making a query is creating a new `PostgresConnection`. The minimum requirements to create one are a `SocketAddress` and `EventLoop`. 
+
+```swift
+import NIOPostgres
+
+let eventLoop: EventLoop = ...
+let conn = try PostgresConnection.connect(
+    to: .makeAddressResolvingHost("my.psql.server", port: 5432),
+    on: eventLoop
+).wait()
+```
+
+Note: These examples will make use of `wait()` for simplicity. This is appropriate if you are using NIOPostgres on the main thread, like for a CLI tool or in tests. However, you should never use `wait()` on an event loop.
+
+There are a few ways to create a `SocketAddress`:
+
+- `init(ipAddress: String, port: Int)`
+- `init(unixDomainSocketPath: String)`
+- `makeAddressResolvingHost(_ host: String, port: Int)`
+
+There are also some additional arguments you can supply to `connect`. 
+
+- `tlsConfiguration` An optional `TLSConfiguration` struct. If supplied, the PostgreSQL connection will be upgraded to use SSL.
+- `serverHostname` An optional `String` to use in conjunction with `tlsConfiguration` to specify the server's hostname. 
+
+`connect` will return a future `PostgresConnection`, or an error if it could not connect.
+
+### Client Protocol
+
+Interaction with a server revolves around the `PostgresClient` protocol. This protocol includes methods like `query(_:)` for executing SQL queries and reading the resulting rows. 
+
+`PostgresConnection` is the default implementation of `PostgresClient` provided by this package. Assume the client here is the connection from the previous example.
+
+```swift
+import NIOPostgres
+
+let client: PostgresClient = ...
+// now we can use client to do queries
+```
+
+### Simple Query
+
+Simple (or text) queries allow you to execute a SQL string on the connected PostgreSQL server. These queries do not support binding parameters, so any values sent must be escaped manually.
+
+These queries are most useful for schema or transactional queries, or simple selects. Note that values returned by simple queries will be transferred in the less efficient text format. 
+
+`simpleQuery` has two overloads, one that returns an array of rows, and one that accepts a closure for handling each row as it is returned.
+
+```swift
+let rows = try client.simpleQuery("SELECT version()").wait()
+print(rows) // [["version": "11.0.0"]]
+
+try client.simpleQuery("SELECT version()") { row in
+    print(row) // ["version": "11.0.0"]
+}.wait()
+```
+
+### Parameterized Query
+
+Parameterized (or binary) queries allow you to execute a SQL string on the connected PostgreSQL server. These queries support passing bound parameters as a separate argument. Each parameter is represented in the SQL string using incrementing placeholders, starting at `$1`. 
+
+These queries are most useful for selecting, inserting, and updating data. Data for these queries is transferred using the highly efficient binary format. 
+
+Just like `simpleQuery`, `query` also offers two overloads. One that returns an array of rows, and one that accepts a closure for handling each row as it is returned.
+
+```swift
+let rows = try client.query("SELECT * FROM planets WHERE name = $1", ["Earth"]).wait()
+print(rows) // [["id": 42, "name": "Earth"]]
+
+try client.query("SELECT * FROM planets WHERE name = $1", ["Earth"]) { row in
+    print(row) // ["id": 42, "name": "Earth"]
+}.wait()
+```
+
+### Rows and Data
+
+Both `simpleQuery` and `query` return the same `PostgresRow` type. Columns can be fetched from the row using the `column(_: String)` method.
+
+```swift
+let row: PostgresRow = ...
+let version = row.column("version")
+print(version) // PostgresData?
+```
+
+`PostgresRow` columns are stored as `PostgresData`. This struct contains the raw bytes returned by PostgreSQL as well as some information for parsing them, such as:
+
+- Postgres column type
+- Wire format: binary or text
+- Value as array of bytes
+
+`PostgresData` has a variety of convenience methods for converting column data to usable Swift types.
+
+```swift
+let data: PostgresData= ...
+
+print(data.string) // String?
+
+print(data.int) // Int?
+print(data.int8) // Int8?
+print(data.int16) // Int16?
+print(data.int32) // Int32?
+print(data.int64) // Int64?
+
+print(data.uint) // UInt?
+print(data.uint8) // UInt8?
+print(data.uint16) // UInt16?
+print(data.uint32) // UInt32?
+print(data.uint64) // UInt64?
+
+print(data.float) // Float?
+print(data.double) // Double?
+
+print(data.date) // Date?
+print(data.uuid) // UUID?
+
+print(data.numeric) // PostgresNumeric?
+```
+
+`PostgresData` is also used for sending data _to_ the server via parameterized values. To create `PostgresData` from a Swift type, use the available intializer methods. 

Sources/NIOPostgres/Connection/PostgresConnection.swift

@@ -13,22 +13,34 @@ public final class PostgresConnection {
     }
 
     public var logger: Logger
+
+    private var didClose: Bool
 
     init(channel: Channel, logger: Logger) {
         self.channel = channel
         self.logger = logger
+        self.didClose = false
     }
 
     public func close() -> EventLoopFuture<Void> {
-        guard self.channel.isActive else {
+        guard !self.didClose else {
             return self.eventLoop.makeSucceededFuture(())
         }
-        return self.channel.close()
+        self.didClose = true
+        
+        let promise = self.eventLoop.makePromise(of: Void.self)
+        self.eventLoop.submit {
+            switch self.channel.isActive {
+            case true:
+                promise.succeed(())
+            case false:
+                self.channel.close(mode: .all, promise: promise)
+            }
+        }.cascadeFailure(to: promise)
+        return promise.futureResult
     }
 
     deinit {
-        if self.channel.isActive {
-            assertionFailure("PostgresConnection deinitialized before being closed.")
-        }
+        assert(self.didClose, "PostgresConnection deinitialized before being closed.")
     }
 }

Sources/NIOPostgres/Data/PostgresData+Array.swift

@@ -0,0 +1,104 @@
+extension PostgresData {
+    public init<T>(array: [T])
+        where T: PostgresDataConvertible
+    {
+        let elementType = T.postgresDataType
+        guard let arrayType = elementType.arrayType else {
+            fatalError("No array type for \(elementType)")
+        }
+        var buffer = ByteBufferAllocator().buffer(capacity: 0)
+        // 0 if empty, 1 if not
+        buffer.writeInteger(array.isEmpty ? 0 : 1, as: UInt32.self)
+        // b
+        buffer.writeInteger(0, as: UInt32.self)
+        // array element type
+        buffer.writeInteger(elementType.rawValue)
+
+        // continue if the array is not empty
+        if !array.isEmpty {
+            // length of array
+            buffer.writeInteger(numericCast(array.count), as: UInt32.self)
+            // dimensions
+            buffer.writeInteger(1, as: UInt32.self)
+
+            for item in array {
+                if var value = item.postgresData?.value {
+                    buffer.writeInteger(numericCast(value.readableBytes), as: UInt32.self)
+                    buffer.writeBuffer(&value)
+                } else {
+                    buffer.writeInteger(0, as: UInt32.self)
+                }
+            }
+        }
+
+        self.init(type: arrayType, typeModifier: nil, formatCode: .binary, value: buffer)
+    }
+
+    public func array<T>(of type: T.Type = T.self) -> [T]?
+        where T: PostgresDataConvertible
+    {
+        guard var value = self.value else {
+            return nil
+        }
+        // ensures the data type is actually an array
+        guard self.type.elementType != nil else {
+            return nil
+        }
+        guard let isNotEmpty = value.readInteger(as: UInt32.self) else {
+            return nil
+        }
+        guard let b = value.readInteger(as: UInt32.self) else {
+            return nil
+        }
+        assert(b == 0, "Array b field did not equal zero")
+        guard let type = value.readInteger(as: PostgresDataType.self) else {
+            return nil
+        }
+        guard isNotEmpty == 1 else {
+            return []
+        }
+        guard let length = value.readInteger(as: UInt32.self) else {
+            return nil
+        }
+        assert(length >= 0, "Invalid length")
+
+        guard let dimensions = value.readInteger(as: UInt32.self) else {
+            return nil
+        }
+        assert(dimensions == 1, "Multi-dimensional arrays not yet supported")
+
+        var array: [T] = []
+        while
+            let itemLength = value.readInteger(as: UInt32.self),
+            let itemValue = value.readSlice(length: numericCast(itemLength))
+        {
+            let data = PostgresData(type: type, typeModifier: nil, formatCode: self.formatCode, value: itemValue)
+            guard let t = T(postgresData: data) else {
+                // if we fail to convert any data, fail the entire array
+                return nil
+            }
+            array.append(t)
+        }
+        return array
+    }
+}
+
+extension Array: PostgresDataConvertible where Element: PostgresDataConvertible {
+    public static var postgresDataType: PostgresDataType {
+        guard let arrayType = Element.postgresDataType.arrayType else {
+            fatalError("No array type for \(Element.postgresDataType)")
+        }
+        return arrayType
+    }
+
+    public init?(postgresData: PostgresData) {
+        guard let array = postgresData.array(of: Element.self) else {
+            return nil
+        }
+        self = array
+    }
+
+    public var postgresData: PostgresData? {
+        return PostgresData(array: self)
+    }
+}