imag/lib/entry/libimagentrycategory/src/iter.rs

126 lines
4.3 KiB
Rust

//
// imag - the personal information management suite for the commandline
// Copyright (C) 2015-2018 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::storeid::StoreIdIterator;
use libimagstore::store::Store;
use libimagstore::store::FileLockEntry;
use toml_query::read::TomlValueReadTypeExt;
use error::Result;
use error::CategoryError as CE;
use error::CategoryErrorKind as CEK;
use store::CATEGORY_REGISTER_NAME_FIELD_PATH;
use entry::EntryCategory;
use error::ResultExt;
/// Iterator for Category names
///
/// Iterates over Result<Category>
///
/// # Return values
///
/// In each iteration, a Option<Result<Category>> is returned. Error kinds are as follows:
///
/// * CategoryErrorKind::StoreReadError if a name could not be fetched from the store
/// * CategoryErrorKind::HeaderReadError if the header of the fetched item couldn't be read
/// * CategoryErrorKind::TypeError if the name could not be fetched because it is not a String
///
pub struct CategoryNameIter<'a>(&'a Store, StoreIdIterator);
impl<'a> CategoryNameIter<'a> {
pub(crate) fn new(store: &'a Store, sidit: StoreIdIterator) -> CategoryNameIter<'a> {
CategoryNameIter(store, sidit)
}
}
impl<'a> Iterator for CategoryNameIter<'a> {
type Item = Result<String>;
fn next(&mut self) -> Option<Self::Item> {
// TODO: Optimize me with lazy_static
let query = CATEGORY_REGISTER_NAME_FIELD_PATH;
while let Some(sid) = self.1.next() {
match sid {
Err(e) => return Some(Err(e).map_err(CE::from)),
Ok(sid) => {
if sid.is_in_collection(&["category"]) {
let func = |store: &Store| { // hack for returning Some(Result<_, _>)
store
.get(sid)?
.ok_or_else(|| CE::from_kind(CEK::StoreReadError))?
.get_header()
.read_string(query)
.chain_err(|| CEK::HeaderReadError)?
.ok_or_else(|| CE::from_kind(CEK::StoreReadError))
};
return Some(func(&self.0))
}
},
} // else continue
}
None
}
}
pub struct CategoryEntryIterator<'a>(&'a Store, StoreIdIterator, String);
impl<'a> CategoryEntryIterator<'a> {
pub(crate) fn new(store: &'a Store, sit: StoreIdIterator, name: String) -> Self {
CategoryEntryIterator(store, sit, name)
}
}
impl<'a> Iterator for CategoryEntryIterator<'a> {
type Item = Result<FileLockEntry<'a>>;
fn next(&mut self) -> Option<Self::Item> {
while let Some(next) = self.1.next() {
match next {
Err(e) => return Some(Err(e).map_err(CE::from)),
Ok(next) => {
let getter = |next| -> Result<(String, FileLockEntry<'a>)> {
let entry = self.0
.get(next)?
.ok_or_else(|| CE::from_kind(CEK::StoreReadError))?;
Ok((entry.get_category()?, entry))
};
match getter(next) {
Err(e) => return Some(Err(e)),
Ok((c, e)) => {
if c == self.2 {
return Some(Ok(e))
// } else {
// continue
}
}
}
}
}
}
None
}
}