add curl bindings for Spottie frontend to communicate with PlayerCore

Spottie/Backend/CURL/CurlClient.swift

@@ -0,0 +1,124 @@
+//
+//  CurlClient.swift
+//  Spottie
+//
+//  Created by Lee Jun Kit on 19/8/21.
+//
+
+import Foundation
+
+class CurlReceivedData {
+    var data: Data?
+    init() {}
+}
+
+class CurlBodyData {
+    var data: Data
+    var bytesLeftToCopy: Int
+    init(_ d: Data) {
+        data = d
+        bytesLeftToCopy = d.count
+    }
+}
+
+enum CurlError: Error {
+    case unknown
+}
+
+struct CurlClient {
+    let socketPath: String
+    let queue = DispatchQueue(label: "ljk.spottie.curl", qos: .userInteractive)
+    let curl = curl_easy_init()
+    let readFunc: curl_read_callback = { (buffer, size, num, p) -> Int in
+        let wrapper = Unmanaged<CurlBodyData>.fromOpaque(p!).takeRetainedValue()
+        let bufferSize = size * num
+
+        var numBytesToCopy = wrapper.bytesLeftToCopy
+        if numBytesToCopy == 0 {
+            Unmanaged<CurlBodyData>.fromOpaque(p!).release()
+            return 0
+        }
+
+        if numBytesToCopy > bufferSize {
+            numBytesToCopy = bufferSize
+        }
+
+        // perform the copy
+        let start = wrapper.data.count - wrapper.bytesLeftToCopy
+        let range = start..<(start+numBytesToCopy)
+        let bufferPointer = UnsafeMutableRawBufferPointer(start: buffer, count: bufferSize)
+        let numBytesCopied = wrapper.data.copyBytes(to: bufferPointer, from: range)
+
+        // update the state
+        wrapper.bytesLeftToCopy = wrapper.bytesLeftToCopy - numBytesCopied
+        return numBytesCopied
+    }
+
+    let writeFunc: curl_write_callback = { (buffer, size, num, p) -> Int in
+        let received = Unmanaged<CurlReceivedData>.fromOpaque(p!).takeUnretainedValue()
+        let bytes = UnsafeRawPointer(buffer!)
+        let length = size * num
+        let data = Data(bytes: bytes, count: length)
+        received.data = data
+        return length
+    }
+
+    init(socketPath: String) {
+        self.socketPath = socketPath
+    }
+
+    func run(_ originalReq: URLRequest) async -> Result<CurlReceivedData, CurlError> {
+        let req = (originalReq as NSURLRequest).copy() as! URLRequest
+        return await withCheckedContinuation { continuation in
+            queue.async {
+                curl_easy_setopt_long(curl, CURLOPT_VERBOSE, 1)
+                curl_easy_setopt_string(curl, CURLOPT_UNIX_SOCKET_PATH, socketPath)
+
+                // convert the request into CURL arguments
+                curl_easy_setopt_string(curl, CURLOPT_URL, req.url?.absoluteString)
+
+                // set post
+                if req.httpMethod == "POST" {
+                    curl_easy_setopt_long(curl, CURLOPT_POST, 1)
+                }
+
+                // handle request body
+                if let body = req.httpBody {
+                    curl_easy_setopt_func_read(curl, CURLOPT_READFUNCTION, readFunc)
+                    let bodyWrapper = CurlBodyData(body)
+                    let bodyWrapperPointer = Unmanaged.passRetained(bodyWrapper).toOpaque()
+                    curl_easy_setopt_pointer(curl, CURLOPT_READDATA, bodyWrapperPointer)
+                    curl_easy_setopt_long(curl, CURLOPT_POSTFIELDSIZE, bodyWrapper.data.count)
+                }
+
+                // handle headers
+                var slist: UnsafeMutablePointer<curl_slist>? = nil
+                if let reqHeaders = req.allHTTPHeaderFields {
+                    for (key, value) in reqHeaders {
+                        slist = curl_slist_append(slist, "\(key): \(value)")
+                    }
+                }
+                curl_easy_setopt_slist(curl, CURLOPT_HTTPHEADER, slist)
+
+                // setup write function
+                let received = CurlReceivedData()
+                let pointer = Unmanaged.passUnretained(received).toOpaque()
+                curl_easy_setopt_func_write(curl, CURLOPT_WRITEFUNCTION, writeFunc)
+                curl_easy_setopt_pointer(curl, CURLOPT_WRITEDATA, pointer)
+
+                let res = curl_easy_perform(curl)
+                if res == CURLE_OK {
+                    var code: Int64 = 0
+                    curl_easy_getinfo_long(curl, CURLINFO_RESPONSE_CODE, &code)
+                    continuation.resume(returning: Result.success(received))
+                } else {
+                    continuation.resume(returning: Result.failure(CurlError.unknown))
+                }
+
+                // cleanup
+                curl_slist_free_all(slist)
+                curl_easy_reset(curl)
+            }
+        }
+    }
+}

Spottie/Backend/CURL/spottie_curl.c

@@ -7,10 +7,45 @@
 
 #include "spottie_curl.h"
 
+CURLcode curl_easy_setopt_long(CURL *curl, CURLoption option, long param) {
+    return curl_easy_setopt(curl, option, param);
+}
+
 CURLcode curl_easy_setopt_string(CURL *curl, CURLoption option, const char *param) {
     return curl_easy_setopt(curl, option, param);
 }
 
 CURLcode curl_easy_setopt_bool(CURL *curl, CURLoption option, bool param) {
     return curl_easy_setopt(curl, option, param);
 }
+
+CURLcode curl_easy_setopt_slist(CURL *curl, CURLoption option, struct curl_slist *param) {
+    return curl_easy_setopt(curl, option, param);
+}
+
+CURLcode curl_easy_setopt_func_write(CURL *curl, CURLoption option, curl_write_callback param) {
+    return curl_easy_setopt(curl, option, param);
+}
+
+CURLcode curl_easy_setopt_func_read(CURL *curl, CURLoption option, curl_read_callback param) {
+    return curl_easy_setopt(curl, option, param);
+}
+
+CURLcode curl_easy_setopt_pointer(CURL *curl, CURLoption option, void *param) {
+    return curl_easy_setopt(curl, option, param);
+}
+
+CURLcode curl_easy_getinfo_long(CURL *handle, CURLINFO option, int64_t *param)
+{
+    return curl_easy_getinfo(handle, option, param);
+}
+
+CURLcode curl_easy_getinfo_string(CURL *handle, CURLINFO option, const char **param)
+{
+    return curl_easy_getinfo(handle, option, param);
+}
+
+CURLcode curl_easy_getinfo_double(CURL *handle, CURLINFO option, double *param)
+{
+    return curl_easy_getinfo(handle, option, param);
+}

Spottie/Backend/CURL/spottie_curl.h

@@ -11,7 +11,15 @@
 #include <stdbool.h>
 #include <curl/curl.h>
 
+CURLcode curl_easy_setopt_long(CURL *curl, CURLoption option, long param);
 CURLcode curl_easy_setopt_string(CURL *curl, CURLoption option, const char *param);
 CURLcode curl_easy_setopt_bool(CURL *curl, CURLoption option, bool param);
+CURLcode curl_easy_setopt_slist(CURL *handle, CURLoption option, struct curl_slist *param);
+CURLcode curl_easy_setopt_func_write(CURL *curl, CURLoption option, curl_write_callback param);
+CURLcode curl_easy_setopt_func_read(CURL *curl, CURLoption option, curl_read_callback param);
+CURLcode curl_easy_setopt_pointer(CURL *curl, CURLoption option, void *param);
+CURLcode curl_easy_getinfo_long(CURL *handle, CURLINFO option, int64_t *param);
+CURLcode curl_easy_getinfo_string(CURL *handle, CURLINFO option, const char **param);
+CURLcode curl_easy_getinfo_double(CURL *handle, CURLINFO option, double *param);
 
 #endif /* spottie_curl_h */