Clenup env::which

mamba-org · Nov 20, 2023 · fa110f0 · fa110f0
1 parent 7c5f056
commit fa110f0
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Showing 3 changed files with 70 additions and 30 deletions.
diff --git a/libmamba/include/mamba/core/environment.hpp b/libmamba/include/mamba/core/environment.hpp
@@ -7,14 +7,60 @@
 #ifndef MAMBA_CORE_ENVIRONMENT_HPP
 #define MAMBA_CORE_ENVIRONMENT_HPP
 
-#include <string>
-#include <vector>
+#include <string_view>
 
 #include "mamba/fs/filesystem.hpp"
+#include "mamba/util/build.hpp"
 
 namespace mamba::env
 {
-    auto which(const std::string& exe, const std::string& override_path = "") -> fs::u8path;
-    auto which(const std::string& exe, const std::vector<fs::u8path>& search_paths) -> fs::u8path;
+    [[nodiscard]] auto which(std::string_view exe, std::string_view override_path = "") -> fs::u8path;
+
+    template <typename Iter>
+    [[nodiscard]] auto which_in(std::string_view exe, Iter search_path_first, Iter search_path_last)
+        -> fs::u8path;
+
+    template <typename Range>
+    [[nodiscard]] auto which_in(std::string_view exe, const Range& search_paths) -> fs::u8path;
+
+    /********************
+     *  Implementaiton  *
+     ********************/
+
+    namespace detail
+    {
+        [[nodiscard]] auto
+        which_in_impl(const fs::u8path& exe, const fs::u8path& dir, const fs::u8path& extension)
+            -> fs::u8path;
+    }
+
+
+    template <typename Iter>
+    auto which_in(std::string_view exe, Iter search_path_first, Iter search_path_last) -> fs::u8path
+    {
+        const auto extension = []() -> fs::u8path
+        {
+            if (util::on_win)
+            {
+                return ".exe";
+            }
+            return "";
+        }();
+
+        for (; search_path_first != search_path_last; ++search_path_first)
+        {
+            if (auto p = detail::which_in_impl(exe, *search_path_first, extension); !p.empty())
+            {
+                return p;
+            }
+        }
+        return "";
+    }
+
+    template <typename Range>
+    auto which_in(std::string_view exe, const Range& search_paths) -> fs::u8path
+    {
+        return which_in(exe, search_paths.cbegin(), search_paths.cend());
+    }
 }
 #endif
diff --git a/libmamba/src/api/install.cpp b/libmamba/src/api/install.cpp
@@ -43,7 +43,7 @@ namespace mamba
         )
         {
             const auto get_python_path = [&]
-            { return env::which("python", get_path_dirs(target_prefix)).string(); };
+            { return env::which_in("python", get_path_dirs(target_prefix)).string(); };
 
             const std::unordered_map<std::string, command_args> other_pkg_mgr_install_instructions{
                 { "pip",

diff --git a/libmamba/src/core/environment.cpp b/libmamba/src/core/environment.cpp
@@ -5,6 +5,7 @@
 // The full license is in the file LICENSE, distributed with this software.
 
 #include <cstdlib>
+#include <optional>
 
 #ifdef _WIN32
 #include <mutex>
@@ -33,26 +34,27 @@ extern "C"
 
 namespace mamba::env
 {
-    fs::u8path which(const std::string& exe, const std::string& override_path)
+    auto which(std::string_view exe, std::string_view override_path) -> fs::u8path
     {
         // TODO maybe add a cache?
-        auto env_path = override_path == "" ? util::get_env("PATH") : override_path;
-        if (env_path)
+        auto env_path = std::string(
+            override_path == "" ? util::get_env("PATH").value_or("") : override_path
+        );
+        if (!env_path.empty())
         {
-            std::string path = env_path.value();
-            const auto parts = util::split(path, util::pathsep());
+            const auto parts = util::split(env_path, util::pathsep());
             const std::vector<fs::u8path> search_paths(parts.begin(), parts.end());
-            return which(exe, search_paths);
+            return which_in(exe, search_paths);
         }
 
 
 #ifndef _WIN32
         if (override_path == "")
         {
             char* pathbuf;
-            size_t n = confstr(_CS_PATH, NULL, static_cast<size_t>(0));
+            size_t n = confstr(_CS_PATH, nullptr, static_cast<size_t>(0));
             pathbuf = static_cast<char*>(malloc(n));
-            if (pathbuf != NULL)
+            if (pathbuf != nullptr)
             {
                 confstr(_CS_PATH, pathbuf, n);
                 return which(exe, pathbuf);
@@ -63,34 +65,26 @@ namespace mamba::env
         return "";  // empty path
     }
 
-    fs::u8path which(const std::string& exe, const std::vector<fs::u8path>& search_paths)
+    namespace detail
     {
-        for (auto& p : search_paths)
+        auto which_in_impl(const fs::u8path& exe, const fs::u8path& dir, const fs::u8path& extension)
+            -> fs::u8path
         {
             std::error_code _ec;  // ignore
-            if (!fs::exists(p, _ec) || !fs::is_directory(p, _ec))
+            if (!fs::exists(dir, _ec) || !fs::is_directory(dir, _ec))
             {
-                continue;
+                return "";  // Not found
             }
 
-#ifdef _WIN32
-            const auto exe_with_extension = exe + ".exe";
-#endif
-            for (const auto& entry : fs::directory_iterator(p, _ec))
+            for (const auto& entry : fs::directory_iterator(dir, _ec))
             {
-                const auto filename = entry.path().filename();
-                if (filename == exe
-
-#ifdef _WIN32
-                    || filename == exe_with_extension
-#endif
-                )
+                auto p = entry.path();
+                if ((p.stem() == exe.stem()) && (p.extension().empty() || p.extension() == extension))
                 {
                     return entry.path();
                 }
             }
+            return "";  // Not found
         }
-
-        return "";  // empty path
     }
 }