[c++/m] Add fileMode fucntion to File

Adds the fileMode function to the File entity
on the c++ and the Matlab side and adds an
appropriate test.

Author: mpsonntag

+nix/File.m

@@ -34,6 +34,10 @@
             check = nix_mx('File::isOpen', obj.nix_handle);
         end
 
+        function mode = file_mode(obj)
+            mode = nix_mx('File::fileMode', obj.nix_handle);
+        end
+
         % ----------------
         % Block methods
         % ----------------

nix_mx.cc

@@ -117,6 +117,7 @@ void mexFunction(int            nlhs,
             .reg("blockCount", GETTER(nix::ndsize_t, nix::File, blockCount))
             .reg("sectionCount", GETTER(nix::ndsize_t, nix::File, sectionCount))
             .reg("isOpen", GETTER(bool, nix::File, isOpen));
+        methods->add("File::fileMode", nixfile::fileMode);
 
         classdef<nix::Block>("Block", methods)
             .desc(&nixblock::describe)

src/nixfile.cc

@@ -36,6 +36,21 @@ namespace nixfile {
         output.set(0, h);
     }
 
+    void fileMode(const extractor &input, infusor &output) {
+        nix::File currObj = input.entity<nix::File>(1);
+        nix::FileMode mode = currObj.fileMode();
+        uint8_t omode;
+
+        switch (mode) {
+        case nix::FileMode::ReadOnly: omode = 0; break;
+        case nix::FileMode::ReadWrite: omode = 1; break;
+        case nix::FileMode::Overwrite: omode = 2; break;
+        default: throw std::invalid_argument("unknown open mode");
+        }
+
+        output.set(0, omode);
+    }
+
     mxArray *describe(const nix::File &fd) {
         struct_builder sb({ 1 }, { "format", "version", "location", "createdAt", "updatedAt" });
         sb.set(fd.format());

src/nixfile.h

@@ -15,6 +15,8 @@ namespace nixfile {
 
     void open(const extractor &input, infusor &output);
 
+    void fileMode(const extractor &input, infusor &output);
+
     mxArray *describe(const nix::File &f);
 
 } // namespace nixfile

tests/TestFile.m

@@ -15,6 +15,7 @@
     funcs{end+1} = @test_read_write;
     funcs{end+1} = @test_overwrite;
     funcs{end+1} = @test_is_open;
+    funcs{end+1} = @test_file_mode;
     funcs{end+1} = @test_create_block;
     funcs{end+1} = @test_block_count;
     funcs{end+1} = @test_create_section;
@@ -50,6 +51,21 @@
     assert(f.is_open());
 end
 
+%% Test: File is open
+function [] = test_file_mode( varargin )
+    testFile = fullfile(pwd,'tests','testRW.h5');
+    f = nix.File(testFile, nix.FileMode.ReadOnly);
+    assert(f.file_mode() == nix.FileMode.ReadOnly);
+
+    clear f;
+    f = nix.File(testFile, nix.FileMode.ReadWrite);
+    assert(f.file_mode() == nix.FileMode.ReadWrite);
+
+    clear f;
+    f = nix.File(testFile, nix.FileMode.Overwrite);
+    assert(f.file_mode() == nix.FileMode.Overwrite);
+end
+
 %% Test: Create Block
 function [] = test_create_block( varargin )
     test_file = nix.File(fullfile(pwd,'tests','testRW.h5'), nix.FileMode.Overwrite);