ENH: Added get_database_metadata (#991)

pyproj4 · Nov 6, 2021 · 3084961 · 3084961
1 parent 61ece93
commit 3084961
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Showing 6 changed files with 68 additions and 2 deletions.
diff --git a/docs/api/database.rst b/docs/api/database.rst
@@ -43,3 +43,9 @@ pyproj.database.query_utm_crs_info
 -----------------------------------
 
 .. autofunction:: pyproj.database.query_utm_crs_info
+
+
+pyproj.database.get_database_metadata
+---------------------------------------
+
+.. autofunction:: pyproj.database.get_database_metadata
diff --git a/docs/history.rst b/docs/history.rst
@@ -11,6 +11,7 @@ Latest
 - ENH: Add support for transforming bounds at the poles in :meth:`pyproj.transformer.Transformer.transform_bounds` (pull #962)
 - ENH: Added :attr:`pyproj.transformer.Transformer.source_crs` & :attr:`pyproj.transformer.Transformer.target_crs` (pull #976)
 - ENH: Added :class:`pyproj.crs.coordinate_operation.PoleRotationNetCDFCFConversion` (issue #948)
+- ENH: Added :func:`pyproj.database.get_database_metadata` (issue #990)
 
 3.2.1
 ------

diff --git a/pyproj/database.pyi b/pyproj/database.pyi
@@ -38,3 +38,5 @@ def query_crs_info(
     contains: bool = False,
     allow_deprecated: bool = False,
 ) -> List[CRSInfo]: ...
+
+def get_database_metadata(key: str) -> Optional[str]: ...
diff --git a/pyproj/database.pyx b/pyproj/database.pyx
@@ -403,3 +403,48 @@ def get_units_map(str auth_name=None, str category=None, bint allow_deprecated=F
         proj_unit_list_destroy(db_unit_list)
         pyproj_context_destroy(context)
     return units_map
+
+
+def get_database_metadata(str key not None):
+    """
+    Return metadata from the database.
+
+    Available keys:
+
+    - DATABASE.LAYOUT.VERSION.MAJOR
+    - DATABASE.LAYOUT.VERSION.MINOR
+    - EPSG.VERSION
+    - EPSG.DATE
+    - ESRI.VERSION
+    - ESRI.DATE
+    - IGNF.SOURCE
+    - IGNF.VERSION
+    - IGNF.DATE
+    - NKG.SOURCE
+    - NKG.VERSION
+    - NKG.DATE
+    - PROJ.VERSION
+    - PROJ_DATA.VERSION : PROJ-data version most compatible with this database.
+
+    Parameters
+    ----------
+    key: str
+        The name of the metadata item to get data for.
+
+    Returns
+    -------
+    Optional[str]:
+        The metatada information if available.
+    """
+    cdef PJ_CONTEXT* context = pyproj_context_create()
+    cdef const char* metadata = NULL
+    try:
+        metadata = proj_context_get_database_metadata(
+            context,
+            cstrdecode(key),
+        )
+        if metadata == NULL:
+            return None
+        return metadata
+    finally:
+        pyproj_context_destroy(context)
diff --git a/pyproj/proj.pxi b/pyproj/proj.pxi
@@ -10,8 +10,9 @@ cdef extern from "proj.h" nogil:
                                        const char *dbPath,
                                        const char *const *auxDbPaths,
                                        const char* const *options)
-    void proj_context_set_ca_bundle_path(PJ_CONTEXT *ctx, const char *path);
-
+    void proj_context_set_ca_bundle_path(PJ_CONTEXT *ctx, const char *path)
+    const char *proj_context_get_database_metadata(PJ_CONTEXT* ctx,
+                                                   const char* key)
     ctypedef struct PJ
     ctypedef struct PJ_CONTEXT
     PJ_CONTEXT *proj_context_create ()

diff --git a/test/test_database.py b/test/test_database.py
@@ -5,6 +5,7 @@
     Unit,
     get_authorities,
     get_codes,
+    get_database_metadata,
     get_units_map,
     query_crs_info,
     query_utm_crs_info,
@@ -249,3 +250,13 @@ def test_query_utm_crs_info__aoi_contains():
         assert crs_info.auth_name == "EPSG"
         assert crs_info.type == PJType.PROJECTED_CRS
         assert not crs_info.deprecated
+
+
+def test_get_database_metadata():
+    epsg_version = get_database_metadata("EPSG.VERSION")
+    assert epsg_version
+    assert isinstance(epsg_version, str)
+
+
+def test_get_database_metadata__invalid():
+    assert get_database_metadata("doesnotexist") is None