basic avatars

filecache.cpp

@@ -0,0 +1,80 @@
+#include "filecache.hpp"
+
+Cache::Cache() {
+    m_tmp_path = std::filesystem::temp_directory_path() / "abaddon-cache";
+    std::filesystem::create_directories(m_tmp_path);
+}
+
+Cache::~Cache() {
+    std::error_code err;
+    if (!std::filesystem::remove_all(m_tmp_path, err))
+        fprintf(stderr, "error removing tmp dir\n");
+}
+
+std::string Cache::SanitizeString(std::string str) {
+    std::string ret;
+    for (const char c : str) {
+        if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z'))
+            ret += c;
+        else
+            ret += '_';
+    }
+    return ret;
+}
+
+void Cache::RespondFromPath(std::filesystem::path path, callback_type cb) {
+    /*if (!std::filesystem::exists(path)) return;
+    FILE *fp = std::fopen(path.string().c_str(), "rb");
+    if (fp == nullptr) return;
+    std::fseek(fp, 0, SEEK_END);
+    int len = std::ftell(fp);
+    std::rewind(fp);
+    std::vector<uint8_t> ret;
+    ret.resize(len);
+    std::fread(ret.data(), 1, len, fp);
+    std::fclose(fp);*/
+    cb(path.string());
+}
+
+void Cache::GetFileFromURL(std::string url, callback_type cb) {
+    auto cache_path = m_tmp_path / SanitizeString(url);
+    if (std::filesystem::exists(cache_path)) {
+        RespondFromPath(cache_path, cb);
+        return;
+    }
+
+    if (m_callbacks.find(url) != m_callbacks.end()) {
+        m_callbacks[url].push_back(cb);
+    } else {
+        m_futures.push_back(cpr::GetCallback(std::bind(&Cache::OnResponse, this, std::placeholders::_1), cpr::Url { url }));
+        m_callbacks[url].push_back(cb);
+    }
+}
+
+// this just seems really yucky
+void Cache::CleanupFutures() {
+    for (auto it = m_futures.begin(); it != m_futures.end();) {
+        if (it->wait_for(std::chrono::seconds(0)) == std::future_status::ready)
+            it = m_futures.erase(it);
+        else
+            it++;
+    }
+}
+
+void Cache::OnResponse(const cpr::Response &r) {
+    CleanupFutures(); // see above comment
+    if (r.error || r.status_code > 300) return;
+
+    std::vector<uint8_t> data(r.text.begin(), r.text.end());
+    auto path = m_tmp_path / SanitizeString(r.url);
+    FILE *fp = std::fopen(path.string().c_str(), "wb");
+    if (fp == nullptr)
+        return;
+    std::fwrite(data.data(), 1, data.size(), fp);
+    std::fclose(fp);
+
+    for (const auto &cb : m_callbacks[r.url]) {
+        cb(path.string());
+    }
+    m_callbacks.erase(r.url);
+}