Merge pull request #20 from OpenVicProject/add/git-info-getter

Add Git information getter

Author: Spartan322

SConstruct

@@ -10,6 +10,7 @@ import SCons
 # Local
 from build.option_handler import OptionsClass
 from build.glob_recursive import GlobRecursive
+from build.git_info import get_git_info
 from build.cache import show_progress
 
 def normalize_path(val, env):
@@ -271,5 +272,6 @@ def FinalizeOptions():
 env.SetupOptions = SetupOptions
 env.FinalizeOptions = FinalizeOptions
 env.GlobRecursive = GlobRecursive
+env.get_git_info = get_git_info
 
 Return("env")

build/git_info.py

@@ -0,0 +1,90 @@
+import os
+import subprocess
+from pathlib import Path
+
+base_folder = Path(__file__).resolve().parent
+
+def get_git_tag():
+    git_tag = os.getenv("OPENVIC_TAG", "<tag missing>")
+    if os.path.exists(".git"):
+        try:
+            result = subprocess.check_output(["git", "describe", "--tags", "--abbrev=0"], encoding="utf-8").strip()
+            if result != "":
+                git_tag = result
+        except (subprocess.CalledProcessError, OSError):
+            # `git` not found in PATH.
+            pass
+    
+    return git_tag
+
+def get_git_release():
+    git_release = os.getenv("OPENVIC_RELEASE", "<release missing>")
+    if os.path.exists(".git"):
+        try:
+            result = subprocess.check_output(["gh", "release", "list", "--json", "name", "-q", ".[0] | .name"], encoding="utf-8").strip()
+            if result != "":
+                git_release = result
+        except (subprocess.CalledProcessError, OSError):
+            # `gh` not found in PATH.
+            git_tag = get_git_tag()
+            if git_tag != "<tag missing>":
+                git_release = git_tag
+    
+    return git_release
+
+def get_git_hash():
+    # Parse Git hash if we're in a Git repo.
+    git_hash = "0000000000000000000000000000000000000000"
+    git_folder = ".git"
+
+    if os.path.isfile(".git"):
+        with open(".git", "r", encoding="utf-8") as file:
+            module_folder = file.readline().strip()
+        if module_folder.startswith("gitdir: "):
+            git_folder = module_folder[8:]
+
+    if os.path.isfile(os.path.join(git_folder, "HEAD")):
+        with open(os.path.join(git_folder, "HEAD"), "r", encoding="utf8") as file:
+            head = file.readline().strip()
+        if head.startswith("ref: "):
+            ref = head[5:]
+            # If this directory is a Git worktree instead of a root clone.
+            parts = git_folder.split("/")
+            if len(parts) > 2 and parts[-2] == "worktrees":
+                git_folder = "/".join(parts[0:-2])
+            head = os.path.join(git_folder, ref)
+            packedrefs = os.path.join(git_folder, "packed-refs")
+            if os.path.isfile(head):
+                with open(head, "r", encoding="utf-8") as file:
+                    git_hash = file.readline().strip()
+            elif os.path.isfile(packedrefs):
+                # Git may pack refs into a single file. This code searches .git/packed-refs file for the current ref's hash.
+                # https://mirrors.edge.kernel.org/pub/software/scm/git/docs/git-pack-refs.html
+                for line in open(packedrefs, "r", encoding="utf-8").read().splitlines():
+                    if line.startswith("#"):
+                        continue
+                    (line_hash, line_ref) = line.split(" ")
+                    if ref == line_ref:
+                        git_hash = line_hash
+                        break
+        else:
+            git_hash = head
+
+    # Get the UNIX timestamp of the build commit.
+    git_timestamp = 0
+    if os.path.exists(".git"):
+        try:
+            git_timestamp = subprocess.check_output(
+                ["git", "log", "-1", "--pretty=format:%ct", "--no-show-signature", git_hash], encoding="utf-8"
+            )
+        except (subprocess.CalledProcessError, OSError):
+            # `git` not found in PATH.
+            pass
+
+    return {
+        "git_hash": git_hash,
+        "git_timestamp": git_timestamp,
+    }
+
+def get_git_info():
+    return {**get_git_hash(), "git_tag": get_git_tag(), "git_release": get_git_release() }