[feat] add portable build storage mode, refs #80

src/path_manager/path_manager.cpp

@@ -1,12 +1,98 @@
 #include "path_manager.h"
 
+#include <cstdint>
 #include <cstdlib>
+#include <vector>
+
+#ifndef CROSSDESK_PORTABLE
+#define CROSSDESK_PORTABLE 0
+#endif
+
+#if CROSSDESK_PORTABLE
+#if defined(__APPLE__)
+#include <mach-o/dyld.h>
+#elif !defined(_WIN32)
+#include <limits.h>
+#include <unistd.h>
+#endif
+#endif
+
+namespace {
+
+#if CROSSDESK_PORTABLE
+std::filesystem::path GetExecutableDirectory() {
+#ifdef _WIN32
+  std::vector<wchar_t> buffer(MAX_PATH);
+  while (true) {
+    DWORD length =
+        GetModuleFileNameW(nullptr, buffer.data(),
+                           static_cast<DWORD>(buffer.size()));
+    if (length == 0) {
+      return {};
+    }
+    if (length < buffer.size()) {
+      return std::filesystem::path(buffer.data(), buffer.data() + length)
+          .parent_path();
+    }
+    if (buffer.size() >= 32768) {
+      return {};
+    }
+    buffer.resize(buffer.size() * 2);
+  }
+#elif defined(__APPLE__)
+  uint32_t size = 0;
+  _NSGetExecutablePath(nullptr, &size);
+  std::vector<char> buffer(size + 1);
+  if (_NSGetExecutablePath(buffer.data(), &size) != 0) {
+    return {};
+  }
+
+  std::error_code ec;
+  std::filesystem::path executable =
+      std::filesystem::weakly_canonical(buffer.data(), ec);
+  if (ec) {
+    executable = buffer.data();
+  }
+  return executable.parent_path();
+#else
+  std::vector<char> buffer(PATH_MAX);
+  while (true) {
+    ssize_t length = readlink("/proc/self/exe", buffer.data(),
+                              buffer.size() - 1);
+    if (length <= 0) {
+      return {};
+    }
+    if (static_cast<size_t>(length) < buffer.size() - 1) {
+      buffer[static_cast<size_t>(length)] = '\0';
+      return std::filesystem::path(buffer.data()).parent_path();
+    }
+    buffer.resize(buffer.size() * 2);
+  }
+#endif
+}
+
+std::filesystem::path GetPortableRootPath() {
+  std::filesystem::path executable_dir = GetExecutableDirectory();
+  if (!executable_dir.empty()) {
+    return executable_dir;
+  }
+
+  std::error_code ec;
+  std::filesystem::path current = std::filesystem::current_path(ec);
+  return ec ? std::filesystem::path(".") : current;
+}
+#endif
+
+}  // namespace
 
 namespace crossdesk {
 
 PathManager::PathManager(const std::string& app_name) : app_name_(app_name) {}
 
 std::filesystem::path PathManager::GetConfigPath() {
+#if CROSSDESK_PORTABLE
+  return GetPortableRootPath() / "data";
+#else
 #ifdef _WIN32
   return GetKnownFolder(FOLDERID_RoamingAppData) / app_name_;
 #elif __APPLE__
@@ -14,9 +100,13 @@ std::filesystem::path PathManager::GetConfigPath() {
 #else
   return GetEnvOrDefault("XDG_CONFIG_HOME", GetHome() + "/.config") / app_name_;
 #endif
+#endif
 }
 
 std::filesystem::path PathManager::GetCachePath() {
+#if CROSSDESK_PORTABLE
+  return GetPortableRootPath() / "data";
+#else
 #ifdef _WIN32
 #ifdef CROSSDESK_DEBUG
   return "cache";
@@ -28,9 +118,13 @@ std::filesystem::path PathManager::GetCachePath() {
 #else
   return GetEnvOrDefault("XDG_CACHE_HOME", GetHome() + "/.cache") / app_name_;
 #endif
+#endif
 }
 
 std::filesystem::path PathManager::GetLogPath() {
+#if CROSSDESK_PORTABLE
+  return GetPortableRootPath() / "logs";
+#else
 #ifdef _WIN32
   return GetKnownFolder(FOLDERID_LocalAppData) / app_name_ / "logs";
 #elif __APPLE__
@@ -38,6 +132,7 @@ std::filesystem::path PathManager::GetLogPath() {
 #else
   return GetCachePath() / "logs";
 #endif
+#endif
 }
 
 bool PathManager::CreateDirectories(const std::filesystem::path& p) {
@@ -93,4 +188,4 @@ std::filesystem::path PathManager::GetEnvOrDefault(const char* env_var,
 
   return std::filesystem::path(def);
 }
-}  // namespace crossdesk
+}  // namespace crossdesk