Refactor tilefetcher for https (#126)

Author: CelliesProjects

README.md

@@ -24,6 +24,18 @@ OSM tiles are quite large at 128kB or insane large at 512kB per tile, so psram i
 You can switch provider and tile format at runtime, or set up a different default tile provider if you want.  
 This library can do it all and is very easy to configure and use.  
 
+### TLS validation note
+
+This project currently uses `setInsecure()` for `WiFiClientSecure` connections, which disables certificate validation.
+
+- Risk: Without TLS validation, responses could in theory be intercepted or altered.  
+This matters most if requests carry secrets (e.g. API keys).
+
+- Practical impact: Standard OpenStreetMap tile servers do not require API keys or credentials.  
+In this case, the main risk is limited to someone tampering with map images.
+
+- Benefit: Simplifies setup and supports multiple tile providers without needing to manage CA certificates.
+
 ## How to use
 
 This library is **PlatformIO only** due to use of modern C++ features. The Arduino IDE is **not** supported.  

src/OpenStreetMap-esp32.cpp

@@ -205,7 +205,7 @@ void OpenStreetMap::updateCache(const tileList &requiredTiles, uint8_t zoom, Til
     if (!jobs.empty())
     {
         runJobs(jobs);
-        log_d("Finished %i jobs in %lu ms - %i ms/job", jobs.size(), millis() - startMS, (millis() - startMS) / jobs.size());
+        log_i("Finished %i jobs in %lu ms - %i ms/job", jobs.size(), millis() - startMS, (millis() - startMS) / jobs.size());
     }
 }
 
@@ -360,17 +360,26 @@ void OpenStreetMap::PNGDraw(PNGDRAW *pDraw)
 
 bool OpenStreetMap::fetchTile(ReusableTileFetcher &fetcher, CachedTile &tile, uint32_t x, uint32_t y, uint8_t zoom, String &result, unsigned long timeout)
 {
-    String url = currentProvider->urlTemplate;
-    url.replace("{x}", String(x));
-    url.replace("{y}", String(y));
-    url.replace("{z}", String(zoom));
-    if (currentProvider->requiresApiKey && strstr(url.c_str(), "{apiKey}"))
-        url.replace("{apiKey}", currentProvider->apiKey);
+    char url[256];
+    if (currentProvider->requiresApiKey)
+    {
+        snprintf(url, sizeof(url),
+                 currentProvider->urlTemplate,
+                 zoom, x, y, currentProvider->apiKey);
+    }
+    else
+    {
+        snprintf(url, sizeof(url),
+                 currentProvider->urlTemplate,
+                 zoom, x, y);
+    }
 
     MemoryBuffer buffer = fetcher.fetchToBuffer(url, result, timeout);
     if (!buffer.isAllocated())
         return false;
 
+    [[maybe_unused]] const unsigned long startMS = millis();
+
     PNG *png = getPNGCurrentCore();
     const int16_t rc = png->openRAM(buffer.get(), buffer.size(), PNGDraw);
     if (rc != PNG_SUCCESS)
@@ -390,10 +399,12 @@ bool OpenStreetMap::fetchTile(ReusableTileFetcher &fetcher, CachedTile &tile, ui
     const int decodeResult = png->decode(0, PNG_FAST_PALETTE);
     if (decodeResult != PNG_SUCCESS)
     {
-        result = "Decoding " + url + " failed with code: " + String(decodeResult);
+        result = "Decoding " + String(url) + " failed with code: " + String(decodeResult);
         return false;
     }
 
+    log_d("decoding %s took %lu ms on core %i", url, millis() - startMS, xPortGetCoreID());
+
     tile.x = x;
     tile.y = y;
     tile.z = zoom;

src/OpenStreetMap-esp32.hpp

@@ -41,7 +41,7 @@
 
 constexpr uint16_t OSM_BGCOLOR = lgfx::color565(32, 32, 128);
 constexpr UBaseType_t OSM_TASK_PRIORITY = 1;
-constexpr uint32_t OSM_TASK_STACKSIZE = 5120;
+constexpr uint32_t OSM_TASK_STACKSIZE = 6144;
 constexpr uint32_t OSM_JOB_QUEUE_SIZE = 50;
 constexpr bool OSM_FORCE_SINGLECORE = false;
 constexpr int OSM_SINGLECORE_NUMBER = 1;