[core] Display modify, expires debug information

include/mbgl/util/time.hpp

@@ -1,6 +1,8 @@
 #ifndef MBGL_UTIL_TIME
 #define MBGL_UTIL_TIME
 
+#include <mbgl/util/chrono.hpp>
+
 #include <string>
 #include <cstdint>
 #include <ctime>
@@ -12,6 +14,9 @@ namespace util {
 // Returns the RFC1123 formatted date. E.g. "Tue, 04 Nov 2014 02:13:24 GMT"
 std::string rfc1123(std::time_t time);
 
+// YYYY-mm-dd HH:MM:SS e.g. "2015-11-26 16:11:23"
+std::string iso8601(std::time_t time);
+
 }
 
 }

src/mbgl/renderer/debug_bucket.cpp

@@ -1,6 +1,7 @@
 #include <mbgl/renderer/debug_bucket.hpp>
 #include <mbgl/renderer/painter.hpp>
 #include <mbgl/shader/plain_shader.hpp>
+#include <mbgl/util/time.hpp>
 
 #include <mbgl/platform/gl.hpp>
 
@@ -9,9 +10,20 @@
 
 using namespace mbgl;
 
-DebugBucket::DebugBucket(const TileID id, const TileData::State state_) : state(state_) {
+DebugBucket::DebugBucket(const TileID id, const TileData::State state_, Seconds modified_, Seconds expires_)
+    : state(state_),
+      modified(modified_),
+      expires(expires_) {
     const std::string text = std::string(id) + " - " + TileData::StateToString(state);
     fontBuffer.addText(text.c_str(), 50, 200, 5);
+
+    if (modified > Seconds::zero() && expires > Seconds::zero()) {
+        const std::string modifiedText = "modified: " + util::iso8601(modified.count());
+        fontBuffer.addText(modifiedText.c_str(), 50, 400, 5);
+
+        const std::string expiresText = "expires: " + util::iso8601(expires.count());
+        fontBuffer.addText(expiresText.c_str(), 50, 600, 5);
+    }
 }
 
 void DebugBucket::drawLines(PlainShader& shader) {

src/mbgl/renderer/debug_bucket.hpp

@@ -4,6 +4,7 @@
 #include <mbgl/map/tile_data.hpp>
 #include <mbgl/geometry/debug_font_buffer.hpp>
 #include <mbgl/geometry/vao.hpp>
+#include <mbgl/util/chrono.hpp>
 
 namespace mbgl {
 
@@ -11,12 +12,14 @@ class PlainShader;
 
 class DebugBucket : private util::noncopyable {
 public:
-    DebugBucket(TileID id, TileData::State);
+    DebugBucket(TileID id, TileData::State, Seconds modified, Seconds expires);
 
     void drawLines(PlainShader& shader);
     void drawPoints(PlainShader& shader);
 
     const TileData::State state;
+    const Seconds modified;
+    const Seconds expires;
 
 private:
     DebugFontBuffer fontBuffer;

src/mbgl/renderer/painter_debug.cpp

@@ -24,8 +24,10 @@ void Painter::renderDebugText(TileData& tileData, const mat4 &matrix) {
 
     config.depthTest = GL_FALSE;
 
-    if (!tileData.debugBucket || tileData.debugBucket->state != tileData.getState()) {
-        tileData.debugBucket = std::make_unique<DebugBucket>(tileData.id, tileData.getState());
+    if (!tileData.debugBucket || tileData.debugBucket->state != tileData.getState()
+                              || tileData.debugBucket->modified != tileData.modified
+                              || tileData.debugBucket->expires != tileData.expires) {
+        tileData.debugBucket = std::make_unique<DebugBucket>(tileData.id, tileData.getState(), tileData.modified, tileData.expires);
     }
 
     config.program = plainShader->program;

src/mbgl/util/time.cpp

@@ -19,5 +19,13 @@ std::string rfc1123(std::time_t time) {
     return buffer;
 }
 
+std::string iso8601(std::time_t time) {
+    std::tm info;
+    gmtime_r(&time, &info);
+    char buffer[30];
+    std::strftime(buffer, sizeof(buffer), "%F %T", &info);
+    return buffer;
+}
+
 }
 }