Merge pull request #2330 from juj/fs-tracking

fs-tracking

4 files changed, 115 insertions, 1 deletions

diff --git a/src/library_fs.js b/src/library_fs.js
index d53210f9..5f7f1dea 100644
--- a/src/library_fs.js
+++ b/src/library_fs.js
@@ -26,7 +26,13 @@ mergeInto(LibraryManager.library, {
     // This is set to false when the runtime is initialized, allowing you
     // to modify the filesystem freely before run() is called.
     ignorePermissions: true,
-    
+    trackingDelegate: {},
+    tracking: {
+      openFlags: {
+        READ: 1 << 0,
+        WRITE: 1 << 1
+      }
+    },
     ErrnoError: null, // set during init
     genericErrors: {},
 
@@ -713,6 +719,13 @@ mergeInto(LibraryManager.library, {
           throw new FS.ErrnoError(err);
         }
       }
+      try {
+        if (FS.trackingDelegate['willMovePath']) {
+          FS.trackingDelegate['willMovePath'](old_path, new_path);
+        }
+      } catch(e) {
+        console.log("FS.trackingDelegate['willMovePath']('"+old_path+"', '"+new_path+"') threw an exception: " + e.message);
+      }
       // remove the node from the lookup hash
       FS.hashRemoveNode(old_node);
       // do the underlying fs rename
@@ -725,6 +738,11 @@ mergeInto(LibraryManager.library, {
         // changed its name)
         FS.hashAddNode(old_node);
       }
+      try {
+        if (FS.trackingDelegate['onMovePath']) FS.trackingDelegate['onMovePath'](old_path, new_path);
+      } catch(e) {
+        console.log("FS.trackingDelegate['onMovePath']('"+old_path+"', '"+new_path+"') threw an exception: " + e.message);
+      }
     },
     rmdir: function(path) {
       var lookup = FS.lookupPath(path, { parent: true });
@@ -741,8 +759,20 @@ mergeInto(LibraryManager.library, {
       if (FS.isMountpoint(node)) {
         throw new FS.ErrnoError(ERRNO_CODES.EBUSY);
       }
+      try {
+        if (FS.trackingDelegate['willDeletePath']) {
+          FS.trackingDelegate['willDeletePath'](path);
+        }
+      } catch(e) {
+        console.log("FS.trackingDelegate['willDeletePath']('"+path+"') threw an exception: " + e.message);
+      }
       parent.node_ops.rmdir(parent, name);
       FS.destroyNode(node);
+      try {
+        if (FS.trackingDelegate['onDeletePath']) FS.trackingDelegate['onDeletePath'](path);
+      } catch(e) {
+        console.log("FS.trackingDelegate['onDeletePath']('"+path+"') threw an exception: " + e.message);
+      }
     },
     readdir: function(path) {
       var lookup = FS.lookupPath(path, { follow: true });
@@ -769,8 +799,20 @@ mergeInto(LibraryManager.library, {
       if (FS.isMountpoint(node)) {
         throw new FS.ErrnoError(ERRNO_CODES.EBUSY);
       }
+      try {
+        if (FS.trackingDelegate['willDeletePath']) {
+          FS.trackingDelegate['willDeletePath'](path);
+        }
+      } catch(e) {
+        console.log("FS.trackingDelegate['willDeletePath']('"+path+"') threw an exception: " + e.message);
+      }
       parent.node_ops.unlink(parent, name);
       FS.destroyNode(node);
+      try {
+        if (FS.trackingDelegate['onDeletePath']) FS.trackingDelegate['onDeletePath'](path);
+      } catch(e) {
+        console.log("FS.trackingDelegate['onDeletePath']('"+path+"') threw an exception: " + e.message);
+      }
     },
     readlink: function(path) {
       var lookup = FS.lookupPath(path);
@@ -965,6 +1007,20 @@ mergeInto(LibraryManager.library, {
           Module['printErr']('read file: ' + path);
         }
       }
+      try {
+        if (FS.trackingDelegate['onOpenFile']) {
+          var trackingFlags = 0;
+          if ((flags & {{{ cDefine('O_ACCMODE') }}}) !== {{{ cDefine('O_WRONLY') }}}) {
+            trackingFlags |= FS.tracking.openFlags.READ;
+          }
+          if ((flags & {{{ cDefine('O_ACCMODE') }}}) !== {{{ cDefine('O_RDONLY') }}}) {
+            trackingFlags |= FS.tracking.openFlags.WRITE;
+          }
+          FS.trackingDelegate['onOpenFile'](path, trackingFlags);
+        }
+      } catch(e) {
+        console.log("FS.trackingDelegate['onOpenFile']('"+path+"', flags) threw an exception: " + e.message);
+      }
       return stream;
     },
     close: function(stream) {
@@ -1034,6 +1090,11 @@ mergeInto(LibraryManager.library, {
       }
       var bytesWritten = stream.stream_ops.write(stream, buffer, offset, length, position, canOwn);
       if (!seeking) stream.position += bytesWritten;
+      try {
+        if (stream.path && FS.trackingDelegate['onWriteToFile']) FS.trackingDelegate['onWriteToFile'](stream.path);
+      } catch(e) {
+        console.log("FS.trackingDelegate['onWriteToFile']('"+path+"') threw an exception: " + e.message);
+      }
       return bytesWritten;
     },
     allocate: function(stream, offset, length) {
diff --git a/tests/fs/test_trackingdelegate.c b/tests/fs/test_trackingdelegate.c
new file mode 100644
index 00000000..6cdece72
--- /dev/null
+++ b/tests/fs/test_trackingdelegate.c
@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <emscripten.h>
+
+int main() {
+
+  EM_ASM(
+    FS.trackingDelegate['willMovePath'] = function(oldpath, newpath) {
+      Module.print('About to move "' + oldpath + '" to "' + newpath + '"');
+    };
+    FS.trackingDelegate['onMovePath'] = function(oldpath, newpath) {
+      Module.print('Moved "' + oldpath + '" to "' + newpath + '"');
+    };
+    FS.trackingDelegate['willDeletePath'] = function(path) {
+      Module.print('About to delete "' + path + '"');
+    };
+    FS.trackingDelegate['onDeletePath'] = function(path) {
+      Module.print('Deleted "' + path + '"');
+    };
+    FS.trackingDelegate['onOpenFile'] = function(path, flags) { 
+      Module.print('Opened "' + path + '" with flags ' + flags);
+    };
+    FS.trackingDelegate['onWriteToFile'] = function(path) {
+      Module.print('Wrote to file "' + path + '"');
+    };
+  );
+
+  FILE *file;
+  file = fopen("/file.txt", "w");
+  fputs("hello!", file);
+  fclose(file);
+  rename("/file.txt", "/renamed.txt");
+  file = fopen("/renamed.txt", "r");
+  char str[256] = {};
+  fgets(str, 255, file);
+  printf("File read returned '%s'\n", str);
+  fclose(file);
+  remove("/renamed.txt");
+}
diff --git a/tests/fs/test_trackingdelegate.out b/tests/fs/test_trackingdelegate.out
new file mode 100644
index 00000000..b3c941c2
--- /dev/null
+++ b/tests/fs/test_trackingdelegate.out
@@ -0,0 +1,9 @@
+Opened "/file.txt" with flags 2
+Wrote to file "/file.txt"
+About to move "/file.txt" to "/renamed.txt"
+Moved "/file.txt" to "/renamed.txt"
+Opened "/renamed.txt" with flags 1
+File read returned 'hello!'
+Wrote to file "/dev/tty"
+About to delete "/renamed.txt"
+Deleted "/renamed.txt"
diff --git a/tests/test_core.py b/tests/test_core.py
index 379559e7..cf2730d0 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -4254,6 +4254,11 @@ def process(filename):
     src = open(path_from_root('tests', 'fs', 'test_nodefs_rw.c'), 'r').read()
     self.do_run(src, 'success', force_c=True, js_engines=[NODE_JS])
 
+  def test_fs_trackingdelegate(self):
+    src = path_from_root('tests', 'fs', 'test_trackingdelegate.c')
+    out = path_from_root('tests', 'fs', 'test_trackingdelegate.out')
+    self.do_run_from_file(src, out)
+
   def test_unistd_access(self):
     self.clear()
     if not self.is_emscripten_abi(): return self.skip('asmjs-unknown-emscripten needed for inline js')