SWIFT-133 Implement new Count API (#331)

Author: kaywux

Sources/MongoSwift/MongoCollection+Read.swift

@@ -79,50 +79,27 @@ extension SyncMongoCollection {
         }
     }
 
-    // TODO: SWIFT-133: mark this method deprecated https://jira.mongodb.org/browse/SWIFT-133
     /**
-     * Counts the number of documents in this collection matching the provided filter.
+     * Counts the number of documents in this collection matching the provided filter. Note that an empty filter will
+     * force a scan of the entire collection. For a fast count of the total documents in a collection see
+     * `estimatedDocumentCount`.
      *
      * - Parameters:
      *   - filter: a `Document`, the filter that documents must match in order to be counted
-     *   - options: Optional `CountOptions` to use when executing the command
+     *   - options: Optional `CountDocumentsOptions` to use when executing the command
      *   - session: Optional `SyncClientSession` to use when executing this command
      *
      * - Returns: The count of the documents that matched the filter
-     *
-     * - Throws:
-     *   - `ServerError.commandError` if an error occurs that prevents the command from performing the write.
-     *   - `UserError.invalidArgumentError` if the options passed in form an invalid combination.
-     *   - `EncodingError` if an error occurs while encoding the options to BSON.
      */
-    public func count(
+    public func countDocuments(
         _ filter: Document = [:],
-        options: CountOptions? = nil,
+        options: CountDocumentsOptions? = nil,
         session: SyncClientSession? = nil
     ) throws -> Int {
-        let operation = CountOperation(collection: self, filter: filter, options: options)
+        let operation = CountDocumentsOperation(collection: self, filter: filter, options: options)
         return try self._client.executeOperation(operation, session: session)
     }
 
-    /**
-     * Counts the number of documents in this collection matching the provided filter.
-     *
-     * - Parameters:
-     *   - filter: a `Document`, the filter that documents must match in order to be counted
-     *   - options: Optional `CountDocumentsOptions` to use when executing the command
-     *   - session: Optional `SyncClientSession` to use when executing this command
-     *
-     * - Returns: The count of the documents that matched the filter
-     */
-    private func countDocuments(
-        _: Document = [:],
-        options _: CountDocumentsOptions? = nil,
-        session _: SyncClientSession? = nil
-    ) throws -> Int {
-        // TODO: SWIFT-133: implement this https://jira.mongodb.org/browse/SWIFT-133
-        throw UserError.logicError(message: "Unimplemented command")
-    }
-
     /**
      * Gets an estimate of the count of documents in this collection using collection metadata.
      *
@@ -132,12 +109,12 @@ extension SyncMongoCollection {
      *
      * - Returns: an estimate of the count of documents in this collection
      */
-    private func estimatedDocumentCount(
-        options _: EstimatedDocumentCountOptions? = nil,
-        session _: SyncClientSession? = nil
+    public func estimatedDocumentCount(
+        options: EstimatedDocumentCountOptions? = nil,
+        session: SyncClientSession? = nil
     ) throws -> Int {
-        // TODO: SWIFT-133: implement this https://jira.mongodb.org/browse/SWIFT-133
-        throw UserError.logicError(message: "Unimplemented command")
+        let operation = EstimatedDocumentCountOperation(collection: self, options: options)
+        return try self._client.executeOperation(operation, session: session)
     }
 
     /**
@@ -263,21 +240,6 @@ public struct AggregateOptions: Codable {
     }
 }
 
-/// The `countDocuments` command takes the same options as the deprecated `count`.
-private typealias CountDocumentsOptions = CountOptions
-
-/// Options to use when executing an `estimatedDocumentCount` command on a `MongoCollection` or a
-/// `SyncMongoCollection`.
-private struct EstimatedDocumentCountOptions {
-    /// The maximum amount of time to allow the query to run.
-    public let maxTimeMS: Int64?
-
-    /// Initializer allowing any/all parameters to be omitted or optional.
-    public init(maxTimeMS: Int64? = nil) {
-        self.maxTimeMS = maxTimeMS
-    }
-}
-
 /// The possible types of `MongoCursor` or `SyncMongoCursor` an operation can return.
 public enum CursorType {
     /**

Sources/MongoSwift/Operations/CountOperation.swift renamed to Sources/MongoSwift/Operations/CountDocumentsOperation.swift

@@ -1,7 +1,7 @@
 import mongoc
 
-/// Options to use when executing a `count` command on a `MongoCollection` or a `SyncMongoCollection`.
-public struct CountOptions: Codable {
+/// Options to use when executing a `countDocuments` command on a `MongoCollection`.
+public struct CountDocumentsOptions: Codable {
     /// Specifies a collation.
     public var collation: Document?
 
@@ -50,12 +50,12 @@ public struct CountOptions: Codable {
 }
 
 /// An operation corresponding to a "count" command on a collection.
-internal struct CountOperation<T: Codable>: Operation {
+internal struct CountDocumentsOperation<T: Codable>: Operation {
     private let collection: SyncMongoCollection<T>
     private let filter: Document
-    private let options: CountOptions?
+    private let options: CountDocumentsOptions?
 
-    internal init(collection: SyncMongoCollection<T>, filter: Document, options: CountOptions?) {
+    internal init(collection: SyncMongoCollection<T>, filter: Document, options: CountDocumentsOptions?) {
         self.collection = collection
         self.filter = filter
         self.options = options
@@ -66,18 +66,7 @@ internal struct CountOperation<T: Codable>: Operation {
         let rp = self.options?.readPreference?._readPreference
         var error = bson_error_t()
         let count = self.collection.withMongocCollection(from: connection) { collPtr in
-            // because we already encode skip and limit in the options,
-            // pass in 0s so we don't get duplicate parameter errors.
-            mongoc_collection_count_with_opts(
-                collPtr,
-                MONGOC_QUERY_NONE,
-                self.filter._bson,
-                0, // skip
-                0, // limit
-                opts?._bson,
-                rp,
-                &error
-            )
+            mongoc_collection_count_documents(collPtr, self.filter._bson, opts?._bson, rp, nil, &error)
         }
 
         guard count != -1 else { throw extractMongoError(error: error) }

Sources/MongoSwift/Operations/EstimatedDocumentCountOperation.swift

@@ -0,0 +1,54 @@
+import mongoc
+
+/// Options to use when executing an `estimatedDocumentCount` command on a `MongoCollection`.
+public struct EstimatedDocumentCountOptions: Codable {
+    /// The maximum amount of time to allow the query to run.
+    public var maxTimeMS: Int64?
+
+    /// A ReadConcern to use for this operation.
+    public var readConcern: ReadConcern?
+
+    // swiftlint:disable redundant_optional_initialization
+    /// A ReadPreference to use for this operation.
+    public var readPreference: ReadPreference? = nil
+    // swiftlint:enable redundant_optional_initialization
+
+    /// Convenience initializer allowing any/all parameters to be optional
+    public init(
+        maxTimeMS: Int64? = nil,
+        readConcern: ReadConcern? = nil,
+        readPreference: ReadPreference? = nil
+    ) {
+        self.maxTimeMS = maxTimeMS
+        self.readConcern = readConcern
+        self.readPreference = readPreference
+    }
+
+    private enum CodingKeys: String, CodingKey {
+        case maxTimeMS, readConcern
+    }
+}
+
+/// An operation corresponding to a "count" command on a collection.
+internal struct EstimatedDocumentCountOperation<T: Codable>: Operation {
+    private let collection: SyncMongoCollection<T>
+    private let options: EstimatedDocumentCountOptions?
+
+    internal init(collection: SyncMongoCollection<T>, options: EstimatedDocumentCountOptions?) {
+        self.collection = collection
+        self.options = options
+    }
+
+    internal func execute(using connection: Connection, session: SyncClientSession?) throws -> Int {
+        let opts = try encodeOptions(options: options, session: session)
+        let rp = self.options?.readPreference?._readPreference
+        var error = bson_error_t()
+        let count = self.collection.withMongocCollection(from: connection) { collPtr in
+            mongoc_collection_estimated_document_count(collPtr, opts?._bson, rp, nil, &error)
+        }
+
+        guard count != -1 else { throw extractMongoError(error: error) }
+
+        return Int(count)
+    }
+}

Tests/MongoSwiftTests/ClientSessionTests.swift

@@ -35,7 +35,8 @@ final class ClientSessionTests: MongoSwiftTestCase {
         (name: "find", body: { _ = try $0.find([:], session: $1).nextOrError() }),
         (name: "aggregate", body: { _ = try $0.aggregate([], session: $1).nextOrError() }),
         (name: "distinct", body: { _ = try $0.distinct(fieldName: "x", session: $1) }),
-        (name: "count", body: { _ = try $0.count(session: $1) })
+        (name: "countDocuments", body: { _ = try $0.countDocuments(session: $1) }),
+        (name: "estimatedDocumentCount", body: { _ = try $0.estimatedDocumentCount(session: $1) })
     ]
 
     // list of write operations on SyncMongoCollection that take in a session

Tests/MongoSwiftTests/CodecTests.swift

@@ -805,7 +805,7 @@ final class CodecTests: MongoSwiftTestCase {
             "writeConcern"
         ]))
 
-        let count = CountOptions(
+        let count = CountDocumentsOptions(
             collation: Document(),
             hint: .indexName("hint"),
             limit: 123,

Tests/MongoSwiftTests/CommandMonitoringTests.swift

@@ -22,9 +22,12 @@ final class CommandMonitoringTests: MongoSwiftTestCase {
             // read in the file data and parse into a struct
             let name = filename.components(separatedBy: ".")[0]
 
-            // remove this if/when bulkwrite is supported
+            // TODO: SWIFT-346: remove this skip
             if name.lowercased().contains("bulkwrite") { continue }
 
+            // remove this when command.json is updated with the new count API (see SPEC-1272)
+            if name.lowercased() == "command" { continue }
+
             print("-----------------------")
             print("Executing tests for file \(name)...\n")
 
@@ -149,7 +152,7 @@ private struct CMTest: Decodable {
 
         switch self.op.name {
         case "count":
-            _ = try? collection.count(filter)
+            _ = try? collection.countDocuments(filter)
         case "deleteMany":
             _ = try? collection.deleteMany(filter)
         case "deleteOne":

Tests/MongoSwiftTests/CrudTests.swift

@@ -30,7 +30,11 @@ final class CrudTests: MongoSwiftTestCase {
             print("\n------------\nExecuting tests from file \(dir)/\(filename)...\n")
 
             // For each file, execute the test cases contained in it
-            for (i, test) in file.tests.enumerated() {
+            for (i, test) in try file.makeTests().enumerated() {
+                if type(of: test) == CountTest.self {
+                    print("Skipping test for old count API, no longer supported by the driver")
+                }
+
                 print("Executing test: \(test.description)")
 
                 // for each test case:
@@ -40,10 +44,18 @@ final class CrudTests: MongoSwiftTestCase {
                 // 4) verify that expected data is present
                 // 5) drop the collection to clean up
                 let collection = db.collection(self.getCollectionName(suffix: "\(filename)_\(i)"))
-                try collection.insertMany(file.data)
+                if !file.data.isEmpty {
+                    try collection.insertMany(file.data)
+                }
                 try test.execute(usingCollection: collection)
                 try test.verifyData(testCollection: collection, db: db)
-                try collection.drop()
+                do {
+                    try collection.drop()
+                } catch let ServerError.commandError(code, _, _, _) where code == 26 {
+                    // ignore ns not found errors
+                } catch {
+                    throw error
+                }
             }
         }
         print() // for readability of results
@@ -64,7 +76,11 @@ final class CrudTests: MongoSwiftTestCase {
 private struct CrudTestFile: Decodable {
     let data: [Document]
     let testDocs: [Document]
-    var tests: [CrudTest] { return try! self.testDocs.map { try makeCrudTest($0) } }
+
+    func makeTests() throws -> [CrudTest] {
+        return try self.testDocs.map { try makeCrudTest($0) }
+    }
+
     let minServerVersion: String?
     let maxServerVersion: String?
 
@@ -88,9 +104,11 @@ private var testTypeMap: [String: CrudTest.Type] = [
     "aggregate": AggregateTest.self,
     "bulkWrite": BulkWriteTest.self,
     "count": CountTest.self,
+    "countDocuments": CountDocumentsTest.self,
     "deleteMany": DeleteTest.self,
     "deleteOne": DeleteTest.self,
     "distinct": DistinctTest.self,
+    "estimatedDocumentCount": EstimatedDocumentCountTest.self,
     "find": FindTest.self,
     "findOneAndDelete": FindOneAndDeleteTest.self,
     "findOneAndUpdate": FindOneAndUpdateTest.self,
@@ -270,10 +288,24 @@ private class BulkWriteTest: CrudTest {
 
 /// A class for executing `count` tests
 private class CountTest: CrudTest {
+    override func execute(usingCollection _: SyncMongoCollection<Document>) throws {}
+}
+
+/// A class for executing `countDocuments` tests
+private class CountDocumentsTest: CrudTest {
     override func execute(usingCollection coll: SyncMongoCollection<Document>) throws {
         let filter: Document = try self.args.get("filter")
-        let options = CountOptions(collation: self.collation, limit: self.limit, skip: self.skip)
-        let result = try coll.count(filter, options: options)
+        let options = CountDocumentsOptions(collation: self.collation, limit: self.limit, skip: self.skip)
+        let result = try coll.countDocuments(filter, options: options)
+        expect(result).to(equal(self.result?.asInt()))
+    }
+}
+
+/// A class for executing `estimatedDocumentCount` tests
+private class EstimatedDocumentCountTest: CrudTest {
+    override func execute(usingCollection coll: SyncMongoCollection<Document>) throws {
+        let options = EstimatedDocumentCountOptions()
+        let result = try coll.estimatedDocumentCount(options: options)
         expect(result).to(equal(self.result?.asInt()))
     }
 }