From cb5ad2ed2d19e51fb2a908f4bfcf54f0d55b7b3f Mon Sep 17 00:00:00 2001
From: Celine Mercier <celine.mercier@metabarcoding.org>
Date: Wed, 5 Jul 2017 15:38:22 +0200
Subject: [PATCH] Added functions to try to open a DMS if it exists

---
 python/obitools3/dms/capi/obidms.pxd |  5 +++--
 python/obitools3/dms/dms.pyx         | 13 +++++++++++++
 src/obidms.c                         | 21 ++++++++++++++++++++-
 src/obidms.h                         | 18 ++++++++++++++++++
 4 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/python/obitools3/dms/capi/obidms.pxd b/python/obitools3/dms/capi/obidms.pxd
index 787c60a..be3fb00 100644
--- a/python/obitools3/dms/capi/obidms.pxd
+++ b/python/obitools3/dms/capi/obidms.pxd
@@ -9,8 +9,9 @@ cdef extern from "obidms.h" nogil:
     ctypedef OBIDMS_t* OBIDMS_p 
 
     OBIDMS_p obi_dms(const_char_p dms_name)
-    OBIDMS_p obi_open_dms(const char* dms_path)
-    OBIDMS_p obi_create_dms(const char* dms_path)
+    OBIDMS_p obi_open_dms(const_char_p dms_path)
+    OBIDMS_p obi_test_open_dms(const_char_p dms_path)
+    OBIDMS_p obi_create_dms(const_char_p dms_path)
     int obi_close_dms(OBIDMS_p dms)
     char* obi_dms_get_dms_path(OBIDMS_p dms)
     char* obi_dms_get_full_path(OBIDMS_p dms, const_char_p path_name)
diff --git a/python/obitools3/dms/dms.pyx b/python/obitools3/dms/dms.pyx
index be61f3b..5ab46cf 100644
--- a/python/obitools3/dms/dms.pyx
+++ b/python/obitools3/dms/dms.pyx
@@ -5,6 +5,7 @@ from libc.stdlib  cimport free
 from cpython.list cimport PyList_Size
 
 from .capi.obidms cimport obi_open_dms, \
+                          obi_test_open_dms, \
                           obi_create_dms, \
                           obi_close_dms, \
                           obi_dms_get_full_path
@@ -52,6 +53,18 @@ cdef class DMS(OBIWrapper):
         dms = OBIWrapper.new(DMS, pointer)
         return dms
    
+
+    @staticmethod
+    def test_open(object dms_name) :
+        cdef OBIDMS_p pointer
+        cdef DMS dms
+        cdef bytes dms_name_b = tobytes(dms_name)
+        pointer = obi_test_open_dms(<const_char_p> dms_name_b)      
+        if pointer == NULL :
+            raise Exception("Failed opening an OBIDMS")
+        dms = OBIWrapper.new(DMS, pointer)
+        return dms
+    
     
     def close(self) :
         '''
diff --git a/src/obidms.c b/src/obidms.c
index 25a1b70..710eb20 100644
--- a/src/obidms.c
+++ b/src/obidms.c
@@ -362,7 +362,7 @@ OBIDMS_p obi_open_dms(const char* dms_path)
 	if (realpath(complete_dms_path, dms->directory_path) == NULL)
 	{
 		obi_set_errno(OBIDMS_UNKNOWN_ERROR);
-		obidebug(1, "\nError getting the absolute path to the DMS directory");
+		obidebug(1, "\nError getting the absolute path to the DMS directory (DMS does not exist)");
 		free(complete_dms_path);
 		return NULL;
 	}
@@ -536,6 +536,25 @@ OBIDMS_p obi_open_dms(const char* dms_path)
 }
 
 
+OBIDMS_p obi_test_open_dms(const char* dms_name)
+{
+	int exists;
+
+	exists = obi_dms_exists(dms_name);
+
+	switch (exists)
+	{
+		case 0:
+			return NULL;
+		case 1:
+			return obi_open_dms(dms_name);
+	};
+
+	obidebug(1, "\nError checking if an OBIDMS directory exists");
+	return NULL;
+}
+
+
 OBIDMS_p obi_dms(const char* dms_name)
 {
 	int exists;
diff --git a/src/obidms.h b/src/obidms.h
index e984397..a7db2f5 100644
--- a/src/obidms.h
+++ b/src/obidms.h
@@ -175,6 +175,24 @@ OBIDMS_p obi_create_dms(const char* dms_name);
 OBIDMS_p obi_open_dms(const char* dms_path);
 
 
+/**
+ * @brief Opens an existing OBITools Data Management instance (OBIDMS).
+ *
+ * @warning No error is printed or saved if the DMS does not exist. For it to be the case, use obi_open_dms().
+ *
+ * @param dms_path A pointer to a C string containing the path to the database.
+ *
+ * @returns A pointer to an OBIDMS structure describing the opened DMS.
+ * @retval NULL if the DMS does not exist or if an error occurred.
+ *
+ * @see obi_open_dms()
+ * @see obi_close_dms()
+ * @since May 2017
+ * @author Celine Mercier (celine.mercier@metabarcoding.org)
+ */
+OBIDMS_p obi_test_open_dms(const char* dms_name);
+
+
 /**
  * @brief Creates or opens a new OBIDMS instance.
  *