Improved deserializeMsgPack() speed by reading several bytes at once

extras/tests/Misc/Readers.cpp

@@ -0,0 +1,166 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+using namespace ARDUINOJSON_NAMESPACE;
+
+TEST_CASE("StdStreamReader") {
+  SECTION("read()") {
+    std::istringstream src("\x01\xFF");
+    StdStreamReader reader(src);
+
+    REQUIRE(reader.read() == 0x01);
+    REQUIRE(reader.read() == 0xFF);
+    REQUIRE(reader.read() == -1);
+  }
+
+  SECTION("readBytes() all at once") {
+    std::istringstream src("ABC");
+    StdStreamReader reader(src);
+
+    char buffer[8] = "abcd";
+    REQUIRE(reader.readBytes(buffer, 4) == 3);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'd');
+  }
+
+  SECTION("readBytes() in two parts") {
+    std::istringstream src("ABCDEF");
+    StdStreamReader reader(src);
+
+    char buffer[12] = "abcdefg";
+    REQUIRE(reader.readBytes(buffer, 4) == 4);
+    REQUIRE(reader.readBytes(buffer + 4, 4) == 2);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'D');
+    REQUIRE(buffer[4] == 'E');
+    REQUIRE(buffer[5] == 'F');
+    REQUIRE(buffer[6] == 'g');
+  }
+}
+
+TEST_CASE("SafeCharPointerReader") {
+  SECTION("read") {
+    SafeCharPointerReader reader("\x01\xFF", 2);
+    REQUIRE(reader.read() == 0x01);
+    REQUIRE(reader.read() == 0xFF);
+    REQUIRE(reader.read() == -1);
+    REQUIRE(reader.read() == -1);
+  }
+
+  SECTION("readBytes() all at once") {
+    SafeCharPointerReader reader("ABCD", 3);
+
+    char buffer[8] = "abcd";
+    REQUIRE(reader.readBytes(buffer, 4) == 3);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'd');
+  }
+
+  SECTION("readBytes() in two parts") {
+    SafeCharPointerReader reader("ABCDEF", 6);
+
+    char buffer[8] = "abcdefg";
+    REQUIRE(reader.readBytes(buffer, 4) == 4);
+    REQUIRE(reader.readBytes(buffer + 4, 4) == 2);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'D');
+    REQUIRE(buffer[4] == 'E');
+    REQUIRE(buffer[5] == 'F');
+    REQUIRE(buffer[6] == 'g');
+  }
+}
+
+TEST_CASE("UnsafeCharPointerReader") {
+  SECTION("read()") {
+    UnsafeCharPointerReader reader("\x01\xFF\x00\x12");
+    REQUIRE(reader.read() == 0x01);
+    REQUIRE(reader.read() == 0xFF);
+    REQUIRE(reader.read() == 0);
+    REQUIRE(reader.read() == 0x12);
+  }
+
+  SECTION("readBytes() all at once") {
+    UnsafeCharPointerReader reader("ABCD");
+
+    char buffer[8] = "abcd";
+    REQUIRE(reader.readBytes(buffer, 3) == 3);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'd');
+  }
+
+  SECTION("readBytes() in two parts") {
+    UnsafeCharPointerReader reader("ABCDEF");
+
+    char buffer[8] = "abcdefg";
+    REQUIRE(reader.readBytes(buffer, 4) == 4);
+    REQUIRE(reader.readBytes(buffer + 4, 2) == 2);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'D');
+    REQUIRE(buffer[4] == 'E');
+    REQUIRE(buffer[5] == 'F');
+    REQUIRE(buffer[6] == 'g');
+  }
+}
+
+TEST_CASE("IteratorReader") {
+  SECTION("read()") {
+    std::string src("\x01\xFF");
+    IteratorReader<std::string::const_iterator> reader(src.begin(), src.end());
+
+    REQUIRE(reader.read() == 0x01);
+    REQUIRE(reader.read() == 0xFF);
+    REQUIRE(reader.read() == -1);
+  }
+
+  SECTION("readBytes() all at once") {
+    std::string src("ABC");
+    IteratorReader<std::string::const_iterator> reader(src.begin(), src.end());
+
+    char buffer[8] = "abcd";
+    REQUIRE(reader.readBytes(buffer, 4) == 3);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'd');
+  }
+
+  SECTION("readBytes() in two parts") {
+    std::string src("ABCDEF");
+    IteratorReader<std::string::const_iterator> reader(src.begin(), src.end());
+
+    char buffer[12] = "abcdefg";
+    REQUIRE(reader.readBytes(buffer, 4) == 4);
+    REQUIRE(reader.readBytes(buffer + 4, 4) == 2);
+
+    REQUIRE(buffer[0] == 'A');
+    REQUIRE(buffer[1] == 'B');
+    REQUIRE(buffer[2] == 'C');
+    REQUIRE(buffer[3] == 'D');
+    REQUIRE(buffer[4] == 'E');
+    REQUIRE(buffer[5] == 'F');
+    REQUIRE(buffer[6] == 'g');
+  }
+}