1 files changed, 129 insertions, 0 deletions
diff --git a/test/src/mbgl/test/util.cpp b/test/src/mbgl/test/util.cpp
new file mode 100644
index 0000000000..ca2282a4b5
--- /dev/null
+++ b/test/src/mbgl/test/util.cpp
@@ -0,0 +1,129 @@
+#include <mbgl/test/util.hpp>
+
+#include <mbgl/map/map.hpp>
+#include <mbgl/platform/log.hpp>
+#include <mbgl/util/image.hpp>
+#include <mbgl/util/io.hpp>
+#include <mbgl/util/chrono.hpp>
+
+#include <mapbox/pixelmatch.hpp>
+
+#include <csignal>
+#include <future>
+
+#include <unistd.h>
+
+namespace mbgl {
+namespace test {
+
+Server::Server(const char* executable) {
+    int input[2];
+    int output[2];
+
+    if (pipe(input)) {
+        throw std::runtime_error("Cannot create server input pipe");
+    }
+    if (pipe(output)) {
+        throw std::runtime_error("Cannot create server output pipe");
+    }
+
+    // Store the parent => child pipe so that we can close it in the destructor.
+    fd = input[1];
+
+    pid_t pid = fork();
+    if (pid < 0) {
+        Log::Error(Event::Setup, "Cannot create server process");
+        exit(1);
+    } else if (pid == 0) {
+        // This is the child process.
+
+        // Connect the parent => child pipe to stdin.
+        while ((dup2(input[0], STDIN_FILENO) == -1) && (errno == EINTR)) {}
+        close(input[0]);
+        close(input[1]);
+
+        // Move the child => parent side of the pipe to stdout.
+        while ((dup2(output[1], STDOUT_FILENO) == -1) && (errno == EINTR)) {}
+        close(output[1]);
+        close(output[0]);
+
+        // Launch the actual server process.
+        int ret = execl(executable, executable, nullptr);
+
+        // This call should not return. In case execl failed, we exit anyway.
+        if (ret < 0) {
+            Log::Error(Event::Setup, "Failed to start server: %s", strerror(errno));
+        }
+        exit(0);
+    } else {
+        // This is the parent process.
+
+        // Close the unneeded sides of the pipes.
+        close(output[1]);
+        close(input[0]);
+
+        // Wait until the server process sends at least 2 bytes or closes the handle.
+        char buffer[2];
+        ssize_t bytes, total = 0;
+        while (total < 2 && (bytes = read(output[0], buffer + total, 2 - total)) != 0) {
+            total += bytes;
+        }
+
+        // Close child => parent pipe.
+        close(output[0]);
+
+        // Check signature
+        if (total != 2 || strncmp(buffer, "OK", 2) != 0) {
+            throw std::runtime_error("Failed to start server: Invalid signature");
+        }
+    }
+}
+
+Server::~Server() {
+    if (fd > 0) {
+        close(fd);
+    }
+}
+
+PremultipliedImage render(Map& map) {
+    std::promise<PremultipliedImage> promise;
+    map.renderStill([&](std::exception_ptr, PremultipliedImage&& image) {
+        promise.set_value(std::move(image));
+    });
+    return promise.get_future().get();
+}
+
+void checkImage(const std::string& base,
+                const PremultipliedImage& actual,
+                double imageThreshold,
+                double pixelThreshold) {
+#if !TEST_READ_ONLY
+    if (getenv("UPDATE")) {
+        util::write_file(base + "/expected.png", encodePNG(actual));
+        return;
+    }
+#endif
+
+    PremultipliedImage expected = decodeImage(util::read_file(base + "/expected.png"));
+    PremultipliedImage diff { expected.width, expected.height };
+
+    ASSERT_EQ(expected.width, actual.width);
+    ASSERT_EQ(expected.height, actual.height);
+
+    double pixels = mapbox::pixelmatch(actual.data.get(),
+                                       expected.data.get(),
+                                       expected.width,
+                                       expected.height,
+                                       diff.data.get(),
+                                       pixelThreshold);
+
+    EXPECT_LE(pixels / (expected.width * expected.height), imageThreshold);
+
+#if !TEST_READ_ONLY
+    util::write_file(base + "/actual.png", encodePNG(actual));
+    util::write_file(base + "/diff.png", encodePNG(diff));
+#endif
+}
+
+} // namespace test
+} // namespace mbgl