fix: Simplify build-system and support editable install

* Switch to using "FetchContent_Populate" instead of custom logic
  for checking archive integrity

* Disambiguate executable location installing it into `s5cmd/bin`

* Add support for editable install using `importlib.metadata` to lookup
  location of executable.

Author: jcfr

CMakeLists.txt

@@ -1,73 +1,31 @@
 cmake_minimum_required(VERSION 3.15...3.26)
 project(${SKBUILD_PROJECT_NAME} LANGUAGES NONE)
 
-function(_check_archive dest_file expected_sha256 output_var)
-  get_filename_component(filename ${dest_file} NAME)
-  message(STATUS "Checking ${filename}")
-
-  if(NOT EXISTS ${dest_file})
-    message(STATUS "Checking ${filename} - nonexistent")
-    set(${output_var} "nonexistent" PARENT_SCOPE)
-    return()
-  endif()
-
-  file(SHA256 ${dest_file} current_hash)
-  if(NOT ${current_hash} STREQUAL ${expected_sha256})
-    message(STATUS "Checking ${filename} - expired")
-    set(${output_var} "expired" PARENT_SCOPE)
-    return()
-  endif()
-
-  message(STATUS "Checking ${filename} - up-to-date")
-  set(${output_var} "ok" PARENT_SCOPE)
-endfunction()
-
 # Set in the current scope the following variables:
 # - s5cmd_archive_url
 # - s5cmd_archive_sha256
 include(${CMAKE_CURRENT_SOURCE_DIR}/s5cmdUrls.cmake)
 
 #
-# Download archive
+# Download & extract archive
 #
-cmake_path(GET s5cmd_archive_url FILENAME archive_filename)
-set(destination_file "${CMAKE_CURRENT_BINARY_DIR}/${archive_filename}")
-
-_check_archive(${destination_file} ${s5cmd_archive_sha256} result)
-
-if(result MATCHES "^(nonexistent|expired)$")
-  message(STATUS "Downloading ${s5cmd_archive_url}")
-  file(
-    DOWNLOAD
-      ${s5cmd_archive_url}
-      ${destination_file}
-    EXPECTED_HASH SHA256=${s5cmd_archive_sha256}
-    )
-elseif(result STREQUAL "ok")
-  # ok
-else()
-  message(FATAL_ERROR "Unknown result value: ${result}")
-endif()
+set(download_dir "${PROJECT_BINARY_DIR}")
+set(extract_dir "${PROJECT_BINARY_DIR}/s5cmd-binary-distribution")
+include(FetchContent)
+FetchContent_Populate(s5cmd
+  URL ${s5cmd_archive_url}
+  URL_HASH SHA256=${s5cmd_archive_sha256}
+  DOWNLOAD_DIR ${download_dir}
+  SOURCE_DIR "${extract_dir}"
+  )
 
 #
-# Extract archive
+# Install executable
 #
-set(executable_name "s5cmd${CMAKE_EXECUTABLE_SUFFIX}")
-
-string(MAKE_C_IDENTIFIER ${archive_filename} extract_subdir)
-set(extract_dir "${CMAKE_CURRENT_BINARY_DIR}/${extract_subdir}")
-message(STATUS "Extracting ${archive_filename} into ${extract_dir}")
-file(ARCHIVE_EXTRACT
-  INPUT ${destination_file}
-  DESTINATION ${extract_dir}
-  PATTERNS "${executable_name}"
-  VERBOSE
-  )
-
 set(_permissions PERMISSIONS
   OWNER_READ OWNER_WRITE OWNER_EXECUTE
   GROUP_READ GROUP_EXECUTE
   WORLD_READ WORLD_EXECUTE
   )
-
-install(PROGRAMS ${extract_dir}/${executable_name} DESTINATION "s5cmd" ${_permissions})
+set(executable_name "s5cmd${CMAKE_EXECUTABLE_SUFFIX}")
+install(PROGRAMS ${extract_dir}/${executable_name} DESTINATION "s5cmd/bin" ${_permissions})

src/s5cmd/__init__.py

@@ -9,6 +9,7 @@
 
 import subprocess
 import sys
+from importlib.metadata import distribution
 from pathlib import Path
 from typing import NoReturn
 
@@ -17,11 +18,19 @@
 __all__ = ["__version__", "s5cmd"]
 
 
-S5CMD_BIN_DIR: Path = Path(__file__).parent
+def _lookup(name: str) -> Path:
+    executable_path = f"s5cmd/bin/{name}"
+    files = distribution("s5cmd").files
+    if files is not None:
+        for _file in files:
+            if str(_file).startswith(executable_path):
+                return Path(_file.locate()).resolve(strict=True)
+    msg = f"Failed to lookup '{executable_path}` directory."
+    raise FileNotFoundError(msg)
 
 
 def _program(name: str, args: list[str]) -> int:
-    return subprocess.call([S5CMD_BIN_DIR / name, *args], close_fds=False)
+    return subprocess.call([_lookup(name), *args], close_fds=False)
 
 
 def s5cmd() -> NoReturn: