Add annotation entry fetcher module

libimagannotation/src/annotation_fetcher.rs

@@ -0,0 +1,116 @@
+//
+// imag - the personal information management suite for the commandline
+// Copyright (C) 2015, 2016 Matthias Beyer <mail@beyermatthias.de> and contributors
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; version
+// 2.1 of the License.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+//
+
+use libimagstore::store::Entry;
+use libimagstore::store::Store;
+use libimagentrylink::internal::InternalLinker;
+use libimagnotes::note::Note;
+use libimagnotes::note::NoteIterator;
+use libimagstore::storeid::StoreIdIterator;
+
+use result::Result;
+use error::AnnotationErrorKind as AEK;
+use error::MapErrInto;
+
+use self::iter::*;
+
+pub trait AnnotationFetcher<'a> {
+
+    fn all_annotations(&'a self) -> Result<AnnotationIter<'a>>;
+
+    fn annotations_for_entry(&'a self, entry: &Entry) -> Result<AnnotationIter<'a>>;
+
+}
+
+impl<'a> AnnotationFetcher<'a> for Store {
+
+    /// Wrapper around `Note::all_notes()` of `libimagnotes` which filters out normal notes and
+    /// leaves only annotations in the iterator.
+    fn all_annotations(&'a self) -> Result<AnnotationIter<'a>> {
+        Note::all_notes(self)
+            .map(|iter| AnnotationIter::new(iter))
+            .map_err_into(AEK::StoreReadError)
+    }
+
+    /// Get all annotations (in an iterator) for an entry
+    ///
+    /// Internally, this fetches the links of the entry, fetches all the entries behind the links
+    /// and filters them for annotations.
+    ///
+    /// This might result in some heavy IO operations if a lot of stuff is linked to a single
+    /// entry, but should normally be not that heavy.
+    fn annotations_for_entry(&'a self, entry: &Entry) -> Result<AnnotationIter<'a>> {
+        entry.get_internal_links()
+            .map_err_into(AEK::StoreReadError)
+            .map(Box::new)
+            .map(|iter| StoreIdIterator::new(iter))
+            .map(|iter| NoteIterator::new(self, iter))
+            .map(|iter| AnnotationIter::new(iter))
+    }
+
+}
+
+pub mod iter {
+    use toml::Value;
+
+    use libimagstore::toml_ext::TomlValueExt;
+    use libimagerror::into::IntoError;
+    use libimagnotes::note::Note;
+    use libimagnotes::note::NoteIterator;
+
+    use result::Result;
+    use error::AnnotationErrorKind as AEK;
+    use error::MapErrInto;
+
+    #[derive(Debug)]
+    pub struct AnnotationIter<'a>(NoteIterator<'a>);
+
+    impl<'a> AnnotationIter<'a> {
+
+        pub fn new(noteiter: NoteIterator<'a>) -> AnnotationIter<'a> {
+            AnnotationIter(noteiter)
+        }
+
+    }
+
+    impl<'a> Iterator for AnnotationIter<'a> {
+        type Item = Result<Note<'a>>;
+
+        fn next(&mut self) -> Option<Result<Note<'a>>> {
+            loop {
+                match self.0.next() {
+                    Some(Ok(note)) => {
+                        let hdr = note.get_header().read("annotation.is_annotation");
+                        match hdr {
+                            Ok(None) => continue, // not an annotation
+                            Ok(Some(Value::Boolean(true))) => return Some(Ok(note)),
+                            Ok(Some(_)) => return Some(Err(AEK::HeaderTypeError.into_error())),
+                            Err(e) => return Some(Err(e).map_err_into(AEK::HeaderReadError)),
+                        }
+                    },
+                    Some(Err(e)) => return Some(Err(e).map_err_into(AEK::StoreReadError)),
+                    None => return None, // iterator consumed
+                }
+            }
+        }
+
+    }
+
+}
+

libimagannotation/src/error.rs

@@ -23,7 +23,9 @@ generate_error_module!(
         StoreWriteError  => "Store write error",
 
         LinkingError     => "Error while linking",
-        HeaderWriteError => "Couldn't write Header for annotation"
+        HeaderWriteError => "Couldn't write Header for annotation",
+        HeaderReadError  => "Couldn't read Header of Entry",
+        HeaderTypeError  => "Header field has unexpected type"
     );
 );
 

libimagannotation/src/lib.rs

@@ -27,6 +27,7 @@ extern crate libimagnotes;
 extern crate libimagutil;
 
 pub mod annotateable;
+pub mod annotation_fetcher;
 pub mod error;
 pub mod result;