Implement cpputils::ProgressBar

src/cpp-utils/CMakeLists.txt

@@ -23,6 +23,7 @@ set(SOURCES
         io/IOStreamConsole.cpp
         io/NoninteractiveConsole.cpp
         io/pipestream.cpp
+        io/ProgressBar.cpp
         thread/LoopThread.cpp
         thread/ThreadSystem.cpp
         thread/debugging_nonwindows.cpp

src/cpp-utils/io/ProgressBar.cpp

@@ -0,0 +1,35 @@
+#include "ProgressBar.h"
+#include <iostream>
+#include <limits>
+#include <mutex>
+#include "IOStreamConsole.h"
+
+using std::string;
+
+namespace cpputils {
+
+ProgressBar::ProgressBar(const char* preamble, uint64_t max_value)
+: ProgressBar(std::make_shared<IOStreamConsole>(), preamble, max_value) {}
+
+ProgressBar::ProgressBar(std::shared_ptr<Console> console, const char* preamble, uint64_t max_value)
+: _console(std::move(console))
+, _preamble(string("\r") + preamble + " ")
+, _max_value(max_value)
+, _lastPercentage(std::numeric_limits<decltype(_lastPercentage)>::max()) {
+    ASSERT(_max_value > 0, "Progress bar can't handle max_value of 0");
+
+    _console->print("\n");
+
+    // show progress bar. _lastPercentage is different to zero, so it shows.
+    update(0);
+}
+
+void ProgressBar::update(uint64_t value) {
+    const size_t percentage = (100 * value) / _max_value;
+    if (percentage != _lastPercentage) {
+        _console->print(_preamble + std::to_string(percentage) + "%");
+        _lastPercentage = percentage;
+    }
+}
+
+}

src/cpp-utils/io/ProgressBar.h

@@ -0,0 +1,31 @@
+#pragma once
+#ifndef MESSMER_CPPUTILS_IO_PROGRESSBAR_H
+#define MESSMER_CPPUTILS_IO_PROGRESSBAR_H
+
+#include <cpp-utils/macros.h>
+#include <string>
+#include <memory>
+#include "Console.h"
+
+namespace cpputils {
+
+class ProgressBar final {
+public:
+    explicit ProgressBar(std::shared_ptr<Console> console, const char* preamble, uint64_t max_value);
+    explicit ProgressBar(const char* preamble, uint64_t max_value);
+
+    void update(uint64_t value);
+
+private:
+
+    std::shared_ptr<Console> _console;
+    std::string _preamble;
+    uint64_t _max_value;
+    size_t _lastPercentage;
+
+    DISALLOW_COPY_AND_ASSIGN(ProgressBar);
+};
+
+}
+
+#endif

test/cpp-utils/CMakeLists.txt

@@ -29,6 +29,7 @@ set(SOURCES
     io/ConsoleTest_Print.cpp
     io/ConsoleTest_Ask.cpp
 	io/ConsoleTest_AskPassword.cpp
+	io/ProgressBarTest.cpp
     random/RandomIncludeTest.cpp
     lock/LockPoolIncludeTest.cpp
     lock/ConditionBarrierIncludeTest.cpp

test/cpp-utils/io/ProgressBarTest.cpp

@@ -0,0 +1,66 @@
+#include <cpp-utils/io/ProgressBar.h>
+#include <gmock/gmock.h>
+
+using cpputils::ProgressBar;
+using std::make_shared;
+
+class MockConsole final: public cpputils::Console {
+public:
+    void EXPECT_OUTPUT(const char* expected) {
+        EXPECT_EQ(expected, _output);
+        _output = "";
+    }
+
+    void print(const std::string& text) override {
+        _output += text;
+    }
+
+    unsigned int ask(const std::string&, const std::vector<std::string>&) override {
+        EXPECT_TRUE(false);
+        return 0;
+    }
+
+    bool askYesNo(const std::string&, bool) override {
+        EXPECT_TRUE(false);
+        return false;
+    }
+
+    std::string askPassword(const std::string&) override {
+        EXPECT_TRUE(false);
+        return "";
+    }
+
+private:
+    std::string _output;
+};
+
+TEST(ProgressBarTest, testProgressBar) {
+    auto console = make_shared<MockConsole>();
+
+    ProgressBar bar(console, "Preamble", 2000);
+    console->EXPECT_OUTPUT("\n\rPreamble 0%");
+
+    // when updating to 0, doesn't reprint
+    bar.update(0);
+    console->EXPECT_OUTPUT("");
+
+    // update to half
+    bar.update(1000);
+    console->EXPECT_OUTPUT("\rPreamble 50%");
+
+    // when updating to same value, doesn't reprint
+    bar.update(1000);
+    console->EXPECT_OUTPUT("");
+
+    // when updating to value with same percentage, doesn't reprint
+    bar.update(1001);
+    console->EXPECT_OUTPUT("");
+
+    // update to 0
+    bar.update(0);
+    console->EXPECT_OUTPUT("\rPreamble 0%");
+
+    // update to full
+    bar.update(2000);
+    console->EXPECT_OUTPUT("\rPreamble 100%");
+}