[core] Make response data shared to avoid excessive copying

10 files changed, 22 insertions, 33 deletions

diff --git a/src/mbgl/map/map_context.cpp b/src/mbgl/map/map_context.cpp
index b197ea12f3..11d631a57a 100644
--- a/src/mbgl/map/map_context.cpp
+++ b/src/mbgl/map/map_context.cpp
@@ -113,7 +113,7 @@ void MapContext::setStyleURL(const std::string& url) {
         styleRequest = nullptr;
 
         if (res.status == Response::Successful) {
-            loadStyleJSON(res.data, base);
+            loadStyleJSON(*res.data, base);
         } else if (res.status == Response::NotFound && styleURL.find("mapbox://") == 0) {
             Log::Error(Event::Setup, "style %s could not be found or is an incompatible legacy map or style", styleURL.c_str());
         } else {
diff --git a/src/mbgl/map/source.cpp b/src/mbgl/map/source.cpp
index 7e30682895..551a9eb190 100644
--- a/src/mbgl/map/source.cpp
+++ b/src/mbgl/map/source.cpp
@@ -163,7 +163,7 @@ void Source::load() {
         }
 
         rapidjson::Document d;
-        d.Parse<0>(res.data.c_str());
+        d.Parse<0>(res.data->c_str());
 
         if (d.HasParseError()) {
             std::stringstream message;
diff --git a/src/mbgl/map/sprite.cpp b/src/mbgl/map/sprite.cpp
index a54d96f005..cbd8c44338 100644
--- a/src/mbgl/map/sprite.cpp
+++ b/src/mbgl/map/sprite.cpp
@@ -20,10 +20,8 @@
 namespace mbgl {
 
 struct Sprite::Loader {
-    bool loadedJSON = false;
-    bool loadedImage = false;
-    std::unique_ptr<Data> data = std::make_unique<Data>();
-
+    std::shared_ptr<const std::string> image;
+    std::shared_ptr<const std::string> json;
     RequestHolder jsonRequest;
     RequestHolder spriteRequest;
 };
@@ -50,8 +48,7 @@ Sprite::Sprite(const std::string& baseUrl, float pixelRatio_)
         }
         loader->jsonRequest = nullptr;
         if (res.status == Response::Successful) {
-            loader->data->json = res.data;
-            loader->loadedJSON = true;
+            loader->json = res.data;
         } else {
             std::stringstream message;
             message << "Failed to load [" << jsonURL << "]: " << res.message;
@@ -70,8 +67,7 @@ Sprite::Sprite(const std::string& baseUrl, float pixelRatio_)
             }
             loader->spriteRequest = nullptr;
             if (res.status == Response::Successful) {
-                loader->data->image = res.data;
-                loader->loadedImage = true;
+                loader->image = res.data;
             } else {
                 std::stringstream message;
                 message << "Failed to load [" << spriteURL << "]: " << res.message;
@@ -88,14 +84,12 @@ Sprite::~Sprite() {
 void Sprite::emitSpriteLoadedIfComplete() {
     assert(loader);
 
-    if (!loader->loadedImage || !loader->loadedJSON || !observer) {
+    if (!loader->image || !loader->json || !observer) {
         return;
     }
 
-    std::unique_ptr<Data> data(std::move(loader->data));
-    loader.reset();
-
-    auto result = parseSprite(data->image, data->json);
+    auto local = std::move(loader);
+    auto result = parseSprite(*local->image, *local->json);
     if (result.is<Sprites>()) {
         loaded = true;
         observer->onSpriteLoaded(result.get<Sprites>());
diff --git a/src/mbgl/map/sprite.hpp b/src/mbgl/map/sprite.hpp
index 32fa16de12..47ce1dbc8b 100644
--- a/src/mbgl/map/sprite.hpp
+++ b/src/mbgl/map/sprite.hpp
@@ -19,11 +19,6 @@ class Request;
 
 class Sprite : private util::noncopyable {
 public:
-    struct Data {
-        std::string image;
-        std::string json;
-    };
-
     class Observer {
     public:
         virtual ~Observer() = default;
diff --git a/src/mbgl/map/vector_tile_data.hpp b/src/mbgl/map/vector_tile_data.hpp
index 1a1ff84061..9b4fa8622b 100644
--- a/src/mbgl/map/vector_tile_data.hpp
+++ b/src/mbgl/map/vector_tile_data.hpp
@@ -42,7 +42,7 @@ private:
     bool parsing = false;
     const SourceInfo& source;
     RequestHolder req;
-    std::string data;
+    std::shared_ptr<const std::string> data;
     float lastAngle = 0;
     float currentAngle;
     float lastPitch = 0;
diff --git a/src/mbgl/storage/default_file_source.cpp b/src/mbgl/storage/default_file_source.cpp
index 5d698fc0f0..3e4c94ce40 100644
--- a/src/mbgl/storage/default_file_source.cpp
+++ b/src/mbgl/storage/default_file_source.cpp
@@ -127,7 +127,6 @@ void DefaultFileSource::Impl::update(DefaultFileRequest* request) {
         if (!request->response->stale && request->response->isExpired()) {
             // Create a new Response object with `stale = true`, but the same data, and
             // replace the current request object we have.
-            // TODO: Make content shared_ptrs so we won't make copies of the content.
             auto response = std::make_shared<Response>(*request->response);
             response->stale = true;
             request->response = response;
diff --git a/src/mbgl/text/glyph_pbf.cpp b/src/mbgl/text/glyph_pbf.cpp
index f351e66c2a..66008adb96 100644
--- a/src/mbgl/text/glyph_pbf.cpp
+++ b/src/mbgl/text/glyph_pbf.cpp
@@ -98,14 +98,15 @@ GlyphPBF::GlyphPBF(GlyphStore* store,
 GlyphPBF::~GlyphPBF() = default;
 
 void GlyphPBF::parse(GlyphStore* store, const std::string& fontStack, const std::string& url) {
-    if (data.empty()) {
+    assert(data);
+    if (data->empty()) {
         // If there is no data, this means we either haven't
         // received any data.
         return;
     }
 
     try {
-        parseGlyphPBF(**store->getFontStack(fontStack), std::move(data));
+        parseGlyphPBF(**store->getFontStack(fontStack), *data);
     } catch (const std::exception& ex) {
         std::stringstream message;
         message <<  "Failed to parse [" << url << "]: " << ex.what();
diff --git a/src/mbgl/text/glyph_pbf.hpp b/src/mbgl/text/glyph_pbf.hpp
index 205824bfe5..bf8567dbec 100644
--- a/src/mbgl/text/glyph_pbf.hpp
+++ b/src/mbgl/text/glyph_pbf.hpp
@@ -42,7 +42,7 @@ private:
 
     void parse(GlyphStore* store, const std::string& fontStack, const std::string& url);
 
-    std::string data;
+    std::shared_ptr<const std::string> data;
     std::atomic<bool> parsed;
 
     RequestHolder req;
diff --git a/src/mbgl/util/worker.cpp b/src/mbgl/util/worker.cpp
index 71c930b4ef..fc599713b3 100644
--- a/src/mbgl/util/worker.cpp
+++ b/src/mbgl/util/worker.cpp
@@ -16,8 +16,8 @@ class Worker::Impl {
 public:
     Impl() = default;
 
-    void parseRasterTile(RasterBucket* bucket, std::string data, std::function<void (TileParseResult)> callback) {
-        std::unique_ptr<util::Image> image(new util::Image(data));
+    void parseRasterTile(RasterBucket* bucket, const std::shared_ptr<const std::string> data, std::function<void (TileParseResult)> callback) {
+        std::unique_ptr<util::Image> image(new util::Image(*data));
         if (!(*image)) {
             callback(TileParseResult("error parsing raster image"));
         }
@@ -29,9 +29,9 @@ public:
         callback(TileParseResult(TileData::State::parsed));
     }
 
-    void parseVectorTile(TileWorker* worker, std::string data, std::function<void (TileParseResult)> callback) {
+    void parseVectorTile(TileWorker* worker, const std::shared_ptr<const std::string> data, std::function<void (TileParseResult)> callback) {
         try {
-            pbf tilePBF(reinterpret_cast<const unsigned char *>(data.data()), data.size());
+            pbf tilePBF(reinterpret_cast<const unsigned char*>(data->data()), data->size());
             callback(worker->parse(VectorTile(tilePBF)));
         } catch (const std::exception& ex) {
             callback(TileParseResult(ex.what()));
@@ -61,12 +61,12 @@ Worker::Worker(std::size_t count) {
 
 Worker::~Worker() = default;
 
-std::unique_ptr<WorkRequest> Worker::parseRasterTile(RasterBucket& bucket, std::string data, std::function<void (TileParseResult)> callback) {
+std::unique_ptr<WorkRequest> Worker::parseRasterTile(RasterBucket& bucket, const std::shared_ptr<const std::string> data, std::function<void (TileParseResult)> callback) {
     current = (current + 1) % threads.size();
     return threads[current]->invokeWithCallback(&Worker::Impl::parseRasterTile, callback, &bucket, data);
 }
 
-std::unique_ptr<WorkRequest> Worker::parseVectorTile(TileWorker& worker, std::string data, std::function<void (TileParseResult)> callback) {
+std::unique_ptr<WorkRequest> Worker::parseVectorTile(TileWorker& worker, const std::shared_ptr<const std::string> data, std::function<void (TileParseResult)> callback) {
     current = (current + 1) % threads.size();
     return threads[current]->invokeWithCallback(&Worker::Impl::parseVectorTile, callback, &worker, data);
 }
diff --git a/src/mbgl/util/worker.hpp b/src/mbgl/util/worker.hpp
index 4e63b45abf..18b1bc92b1 100644
--- a/src/mbgl/util/worker.hpp
+++ b/src/mbgl/util/worker.hpp
@@ -33,12 +33,12 @@ public:
 
     Request parseRasterTile(
         RasterBucket&,
-        std::string data,
+        std::shared_ptr<const std::string> data,
         std::function<void (TileParseResult)> callback);
 
     Request parseVectorTile(
         TileWorker&,
-        std::string data,
+        std::shared_ptr<const std::string> data,
         std::function<void (TileParseResult)> callback);
 
     Request parseLiveTile(