Move just-mr's parsing of git trees to ParseGitTree

...and use it in fetch and repos_to_setup_map to remove code duplication.

3 files changed, 144 insertions, 0 deletions

diff --git a/src/other_tools/utils/TARGETS b/src/other_tools/utils/TARGETS
index 9d4e5734..0987e6e5 100644
--- a/src/other_tools/utils/TARGETS
+++ b/src/other_tools/utils/TARGETS
@@ -65,4 +65,17 @@
   , "private-deps": [["@", "fmt", "", "fmt"]]
   , "stage": ["src", "other_tools", "utils"]
   }
+, "parse_git_tree":
+  { "type": ["@", "rules", "CC", "library"]
+  , "name": ["parse_git_tree"]
+  , "hdrs": ["parse_git_tree.hpp"]
+  , "srcs": ["parse_git_tree.cpp"]
+  , "deps":
+    [ ["src/buildtool/build_engine/expression", "expression"]
+    , ["src/other_tools/ops_maps", "git_tree_fetch_map"]
+    , ["src/utils/cpp", "expected"]
+    ]
+  , "private-deps": [["@", "fmt", "", "fmt"]]
+  , "stage": ["src", "other_tools", "utils"]
+  }
 }
diff --git a/src/other_tools/utils/parse_git_tree.cpp b/src/other_tools/utils/parse_git_tree.cpp
new file mode 100644
index 00000000..dde759b9
--- /dev/null
+++ b/src/other_tools/utils/parse_git_tree.cpp
@@ -0,0 +1,101 @@
+// Copyright 2024 Huawei Cloud Computing Technology Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/other_tools/utils/parse_git_tree.hpp"
+
+#include <map>
+#include <utility>  // std::move
+#include <vector>
+
+#include "fmt/core.h"
+
+[[nodiscard]] auto ParseGitTree(ExpressionPtr const& repo_desc,
+                                std::optional<std::string> origin)
+    -> expected<GitTreeInfo, std::string> {
+    auto repo_desc_hash = repo_desc->At("id");
+    if (not repo_desc_hash) {
+        return unexpected<std::string>{"Mandatory field \"id\" is missing"};
+    }
+    if (not repo_desc_hash->get()->IsString()) {
+        return unexpected{
+            fmt::format("Unsupported value {} for "
+                        "mandatory field \"id\"",
+                        repo_desc_hash->get()->ToString())};
+    }
+
+    auto repo_desc_cmd = repo_desc->At("cmd");
+    if (not repo_desc_cmd) {
+        return unexpected<std::string>{"Mandatory field \"cmd\" is missing"};
+    }
+    if (not repo_desc_cmd->get()->IsList()) {
+        return unexpected{
+            fmt::format("Unsupported value {} for "
+                        "mandatory field \"cmd\"",
+                        repo_desc_cmd->get()->ToString())};
+    }
+    std::vector<std::string> cmd{};
+    for (auto const& token : repo_desc_cmd->get()->List()) {
+        if (token.IsNotNull() and token->IsString()) {
+            cmd.emplace_back(token->String());
+        }
+        else {
+            return unexpected{
+                fmt::format("Unsupported entry {} "
+                            "in mandatory field \"cmd\"",
+                            token->ToString())};
+        }
+    }
+    std::map<std::string, std::string> env{};
+    auto repo_desc_env = repo_desc->Get("env", Expression::none_t{});
+    if (repo_desc_env.IsNotNull() and repo_desc_env->IsMap()) {
+        for (auto const& envar : repo_desc_env->Map().Items()) {
+            if (envar.second.IsNotNull() and envar.second->IsString()) {
+                env.insert({envar.first, envar.second->String()});
+            }
+            else {
+                return unexpected{
+                    fmt::format("Unsupported value {} for "
+                                "key {} in optional field \"envs\"",
+                                envar.second->ToString(),
+                                nlohmann::json(envar.first).dump())};
+            }
+        }
+    }
+    std::vector<std::string> inherit_env{};
+    auto repo_desc_inherit_env =
+        repo_desc->Get("inherit env", Expression::none_t{});
+    if (repo_desc_inherit_env.IsNotNull() and repo_desc_inherit_env->IsList()) {
+        for (auto const& envvar : repo_desc_inherit_env->List()) {
+            if (envvar->IsString()) {
+                inherit_env.emplace_back(envvar->String());
+            }
+            else {
+                return unexpected{
+                    fmt::format("Not a variable "
+                                "name in the specification "
+                                "of \"inherit env\": {}",
+                                envvar->ToString())};
+            }
+        }
+    }
+    // populate struct
+    auto info = GitTreeInfo{.hash = repo_desc_hash->get()->String(),
+                            .env_vars = std::move(env),
+                            .inherit_env = std::move(inherit_env),
+                            .command = std::move(cmd)};
+    if (origin) {
+        info.origin = *std::move(origin);
+    }
+    return info;
+}
diff --git a/src/other_tools/utils/parse_git_tree.hpp b/src/other_tools/utils/parse_git_tree.hpp
new file mode 100644
index 00000000..5aab1a5b
--- /dev/null
+++ b/src/other_tools/utils/parse_git_tree.hpp
@@ -0,0 +1,30 @@
+// Copyright 2024 Huawei Cloud Computing Technology Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef INCLUDED_SRC_OTHER_TOOLS_UTILS_PARSE_GIT_TREE_HPP
+#define INCLUDED_SRC_OTHER_TOOLS_UTILS_PARSE_GIT_TREE_HPP
+
+#include <optional>
+#include <string>
+
+#include "src/buildtool/build_engine/expression/expression.hpp"
+#include "src/other_tools/ops_maps/git_tree_fetch_map.hpp"
+#include "src/utils/cpp/expected.hpp"
+
+[[nodiscard]] auto ParseGitTree(
+    ExpressionPtr const& repo_desc,
+    std::optional<std::string> origin = std::nullopt)
+    -> expected<GitTreeInfo, std::string>;
+
+#endif  // INCLUDED_SRC_OTHER_TOOLS_UTILS_PARSE_GIT_TREE_HPP