imag/libimagentrylink/src/internal.rs

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//
// 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::storeid::StoreId;
use libimagstore::store::Entry;
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use libimagstore::store::Result as StoreResult;
use libimagstore::toml_ext::TomlValueExt;
use libimagerror::into::IntoError;
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use error::LinkErrorKind as LEK;
use error::MapErrInto;
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use result::Result;
use self::iter::LinkIter;
use self::iter::IntoValues;
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use toml::Value;
pub type Link = StoreId;
pub trait InternalLinker {
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/// Get the internal links from the implementor object
fn get_internal_links(&self) -> Result<LinkIter>;
/// Set the internal links for the implementor object
fn set_internal_links(&mut self, links: Vec<&mut Entry>) -> Result<LinkIter>;
/// Add an internal link to the implementor object
fn add_internal_link(&mut self, link: &mut Entry) -> Result<()>;
/// Remove an internal link from the implementor object
fn remove_internal_link(&mut self, link: &mut Entry) -> Result<()>;
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}
pub mod iter {
use std::vec::IntoIter;
use std::cmp::Ordering;
use super::Link;
use error::LinkErrorKind as LEK;
use error::MapErrInto;
use result::Result;
use toml::Value;
use itertools::Itertools;
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use libimagstore::store::Store;
use libimagstore::store::FileLockEntry;
pub struct LinkIter(IntoIter<Link>);
impl LinkIter {
pub fn new(v: Vec<Link>) -> LinkIter {
LinkIter(v.into_iter())
}
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pub fn into_getter(self, store: &Store) -> GetIter {
GetIter(self.0, store)
}
}
impl Iterator for LinkIter {
type Item = Link;
fn next(&mut self) -> Option<Self::Item> {
self.0.next()
}
}
pub trait IntoValues {
fn into_values(self) -> IntoIter<Result<Value>>;
}
impl<I: Iterator<Item = Link>> IntoValues for I {
fn into_values(self) -> IntoIter<Result<Value>> {
self.map(|s| s.without_base().to_str().map_err_into(LEK::InternalConversionError))
.unique_by(|entry| {
match entry {
&Ok(ref e) => Some(e.clone()),
&Err(_) => None,
}
})
.map(|elem| elem.map(Value::String))
.sorted_by(|a, b| {
match (a, b) {
(&Ok(Value::String(ref a)), &Ok(Value::String(ref b))) => Ord::cmp(a, b),
(&Err(_), _) | (_, &Err(_)) => Ordering::Equal,
_ => unreachable!()
}
})
.into_iter()
}
}
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/// An Iterator that `Store::get()`s the Entries from the store while consumed
pub struct GetIter<'a>(IntoIter<Link>, &'a Store);
impl<'a> GetIter<'a> {
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pub fn new(i: IntoIter<Link>, store: &'a Store) -> GetIter<'a> {
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GetIter(i, store)
}
/// Turn this iterator into a LinkGcIter, which `Store::delete()`s entries that are not
/// linked to any other entry.
pub fn delete_unlinked(self) -> DeleteUnlinkedIter<'a> {
DeleteUnlinkedIter(self)
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}
/// Turn this iterator into a FilterLinksIter that removes all entries that are not linked
/// to any other entry, by filtering them out the iterator.
///
/// This does _not_ remove the entries from the store.
pub fn without_unlinked(self) -> FilterLinksIter<'a> {
FilterLinksIter::new(self, Box::new(|links: &[Link]| links.len() > 0))
}
/// Turn this iterator into a FilterLinksIter that removes all entries that have less than
/// `n` links to any other entries.
///
/// This does _not_ remove the entries from the store.
pub fn with_less_than_n_links(self, n: usize) -> FilterLinksIter<'a> {
FilterLinksIter::new(self, Box::new(move |links: &[Link]| links.len() < n))
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}
/// Turn this iterator into a FilterLinksIter that removes all entries that have more than
/// `n` links to any other entries.
///
/// This does _not_ remove the entries from the store.
pub fn with_more_than_n_links(self, n: usize) -> FilterLinksIter<'a> {
FilterLinksIter::new(self, Box::new(move |links: &[Link]| links.len() > n))
}
/// Turn this iterator into a FilterLinksIter that removes all entries where the predicate
/// `F` returns false
///
/// This does _not_ remove the entries from the store.
pub fn filtered_for_links(self, f: Box<Fn(&[Link]) -> bool>) -> FilterLinksIter<'a> {
FilterLinksIter::new(self, f)
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}
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pub fn store(&self) -> &Store {
self.1
}
}
impl<'a> Iterator for GetIter<'a> {
type Item = Result<FileLockEntry<'a>>;
fn next(&mut self) -> Option<Self::Item> {
self.0.next().and_then(|id| match self.1.get(id).map_err_into(LEK::StoreReadError) {
Ok(None) => None,
Ok(Some(x)) => Some(Ok(x)),
Err(e) => Some(Err(e)),
})
}
}
/// An iterator helper that has a function F.
///
/// If the function F returns `false` for the number of links, the entry is ignored, else it is
/// taken.
pub struct FilterLinksIter<'a>(GetIter<'a>, Box<Fn(&[Link]) -> bool>);
impl<'a> FilterLinksIter<'a> {
pub fn new(gi: GetIter<'a>, f: Box<Fn(&[Link]) -> bool>) -> FilterLinksIter<'a> {
FilterLinksIter(gi, f)
}
}
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impl<'a> Iterator for FilterLinksIter<'a> {
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type Item = Result<FileLockEntry<'a>>;
fn next(&mut self) -> Option<Self::Item> {
use internal::InternalLinker;
loop {
match self.0.next() {
Some(Ok(fle)) => {
let links = match fle.get_internal_links().map_err_into(LEK::StoreReadError)
{
Err(e) => return Some(Err(e)),
Ok(links) => links.collect::<Vec<_>>(),
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};
if !(self.1)(&links) {
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continue;
} else {
return Some(Ok(fle));
}
},
Some(Err(e)) => return Some(Err(e)),
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None => break,
}
}
None
}
}
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/// An iterator that removes all Items from the iterator that are not linked anymore by calling
/// `Store::delete()` on them.
///
/// It yields only items which are somehow linked to another entry
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///
/// # Warning
///
/// Deletes entries from the store.
///
pub struct DeleteUnlinkedIter<'a>(GetIter<'a>);
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impl<'a> Iterator for DeleteUnlinkedIter<'a> {
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type Item = Result<FileLockEntry<'a>>;
fn next(&mut self) -> Option<Self::Item> {
use internal::InternalLinker;
loop {
match self.0.next() {
Some(Ok(fle)) => {
let links = match fle.get_internal_links().map_err_into(LEK::StoreReadError)
{
Err(e) => return Some(Err(e)),
Ok(links) => links,
};
if links.count() == 0 {
match self.0
.store()
.delete(fle.get_location().clone())
.map_err_into(LEK::StoreWriteError)
{
Ok(x) => x,
Err(e) => return Some(Err(e)),
}
} else {
return Some(Ok(fle));
}
},
Some(Err(e)) => return Some(Err(e)),
None => break,
}
}
None
}
}
}
impl InternalLinker for Entry {
fn get_internal_links(&self) -> Result<LinkIter> {
process_rw_result(self.get_header().read("imag.links"))
}
/// Set the links in a header and return the old links, if any.
fn set_internal_links(&mut self, links: Vec<&mut Entry>) -> Result<LinkIter> {
use internal::iter::IntoValues;
let self_location = self.get_location().clone();
let mut new_links = vec![];
for link in links {
if let Err(e) = add_foreign_link(link, self_location.clone()) {
return Err(e);
}
let link = link.get_location().clone();
new_links.push(link);
}
let new_links = try!(LinkIter::new(new_links)
.into_values()
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.fold(Ok(vec![]), |acc, elem| {
acc.and_then(move |mut v| {
elem.map_err_into(LEK::InternalConversionError)
.map(|e| {
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v.push(e);
v
})
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})
}));
process_rw_result(self.get_header_mut().set("imag.links", Value::Array(new_links)))
}
fn add_internal_link(&mut self, link: &mut Entry) -> Result<()> {
let new_link = link.get_location().clone();
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debug!("Adding internal link from {:?} to {:?}", self.get_location(), new_link);
add_foreign_link(link, self.get_location().clone())
.and_then(|_| {
self.get_internal_links()
.and_then(|links| {
let links = links.chain(LinkIter::new(vec![new_link]));
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rewrite_links(self.get_header_mut(), links)
})
})
}
fn remove_internal_link(&mut self, link: &mut Entry) -> Result<()> {
let own_loc = self.get_location().clone().without_base();
let other_loc = link.get_location().clone().without_base();
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debug!("Removing internal link from {:?} to {:?}", own_loc, other_loc);
link.get_internal_links()
.and_then(|links| {
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debug!("Rewriting own links for {:?}, without {:?}", other_loc, own_loc);
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rewrite_links(link.get_header_mut(), links.filter(|l| *l != own_loc))
})
.and_then(|_| {
self.get_internal_links()
.and_then(|links| {
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debug!("Rewriting own links for {:?}, without {:?}", own_loc, other_loc);
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rewrite_links(self.get_header_mut(), links.filter(|l| *l != other_loc))
})
})
}
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}
fn rewrite_links<I: Iterator<Item = Link>>(header: &mut Value, links: I) -> Result<()> {
let links = try!(links.into_values()
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.fold(Ok(vec![]), |acc, elem| {
acc.and_then(move |mut v| {
elem.map_err_into(LEK::InternalConversionError)
.map(|e| {
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v.push(e);
v
})
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})
}));
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debug!("Setting new link array: {:?}", links);
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let process = header.set("imag.links", Value::Array(links));
process_rw_result(process).map(|_| ())
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}
/// When Linking A -> B, the specification wants us to link back B -> A.
/// This is a helper function which does this.
fn add_foreign_link(target: &mut Entry, from: StoreId) -> Result<()> {
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debug!("Linking back from {:?} to {:?}", target.get_location(), from);
target.get_internal_links()
.and_then(|links| {
let links = try!(links
.chain(LinkIter::new(vec![from]))
.into_values()
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.fold(Ok(vec![]), |acc, elem| {
acc.and_then(move |mut v| {
elem.map_err_into(LEK::InternalConversionError)
.map(|e| {
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v.push(e);
v
})
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})
}));
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debug!("Setting links in {:?}: {:?}", target.get_location(), links);
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process_rw_result(target.get_header_mut().set("imag.links", Value::Array(links)))
.map(|_| ())
})
}
fn process_rw_result(links: StoreResult<Option<Value>>) -> Result<LinkIter> {
use std::path::PathBuf;
let links = match links {
Err(e) => {
debug!("RW action on store failed. Generating LinkError");
return Err(LEK::EntryHeaderReadError.into_error_with_cause(Box::new(e)))
},
Ok(None) => {
debug!("We got no value from the header!");
return Ok(LinkIter::new(vec![]))
},
Ok(Some(Value::Array(l))) => l,
Ok(Some(_)) => {
debug!("We expected an Array for the links, but there was a non-Array!");
return Err(LEK::ExistingLinkTypeWrong.into());
}
};
if !links.iter().all(|l| is_match!(*l, Value::String(_))) {
debug!("At least one of the Values which were expected in the Array of links is a non-String!");
debug!("Generating LinkError");
return Err(LEK::ExistingLinkTypeWrong.into());
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}
let links : Vec<Link> = try!(links.into_iter()
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.map(|link| {
match link {
Value::String(s) => StoreId::new_baseless(PathBuf::from(s))
.map_err_into(LEK::StoreIdError),
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_ => unreachable!(),
}
})
.collect());
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debug!("Ok, the RW action was successful, returning link vector now!");
Ok(LinkIter::new(links))
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}
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#[cfg(test)]
mod test {
use std::path::PathBuf;
use libimagstore::store::Store;
use super::InternalLinker;
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fn setup_logging() {
use env_logger;
let _ = env_logger::init().unwrap_or(());
}
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pub fn get_store() -> Store {
Store::new(PathBuf::from("/"), None).unwrap()
}
#[test]
fn test_new_entry_no_links() {
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setup_logging();
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let store = get_store();
let entry = store.create(PathBuf::from("test_new_entry_no_links")).unwrap();
let links = entry.get_internal_links();
assert!(links.is_ok());
let links = links.unwrap();
assert_eq!(links.collect::<Vec<_>>().len(), 0);
}
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#[test]
fn test_link_two_entries() {
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setup_logging();
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let store = get_store();
let mut e1 = store.create(PathBuf::from("test_link_two_entries1")).unwrap();
assert!(e1.get_internal_links().is_ok());
let mut e2 = store.create(PathBuf::from("test_link_two_entries2")).unwrap();
assert!(e2.get_internal_links().is_ok());
{
assert!(e1.add_internal_link(&mut e2).is_ok());
let e1_links = e1.get_internal_links().unwrap().collect::<Vec<_>>();
let e2_links = e2.get_internal_links().unwrap().collect::<Vec<_>>();
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debug!("1 has links: {:?}", e1_links);
debug!("2 has links: {:?}", e2_links);
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assert_eq!(e1_links.len(), 1);
assert_eq!(e2_links.len(), 1);
assert!(e1_links.first().map(|l| l.clone().with_base(store.path().clone()) == *e2.get_location()).unwrap_or(false));
assert!(e2_links.first().map(|l| l.clone().with_base(store.path().clone()) == *e1.get_location()).unwrap_or(false));
}
{
assert!(e1.remove_internal_link(&mut e2).is_ok());
println!("{:?}", e2.to_str());
let e2_links = e2.get_internal_links().unwrap().collect::<Vec<_>>();
assert_eq!(e2_links.len(), 0, "Expected [], got: {:?}", e2_links);
println!("{:?}", e1.to_str());
let e1_links = e1.get_internal_links().unwrap().collect::<Vec<_>>();
assert_eq!(e1_links.len(), 0, "Expected [], got: {:?}", e1_links);
}
}
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#[test]
fn test_multiple_links() {
setup_logging();
let store = get_store();
let mut e1 = store.retrieve(PathBuf::from("1")).unwrap();
let mut e2 = store.retrieve(PathBuf::from("2")).unwrap();
let mut e3 = store.retrieve(PathBuf::from("3")).unwrap();
let mut e4 = store.retrieve(PathBuf::from("4")).unwrap();
let mut e5 = store.retrieve(PathBuf::from("5")).unwrap();
assert!(e1.add_internal_link(&mut e2).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert!(e1.add_internal_link(&mut e3).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 2);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert!(e1.add_internal_link(&mut e4).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 3);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert!(e1.add_internal_link(&mut e5).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 4);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert!(e5.remove_internal_link(&mut e1).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 3);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert!(e4.remove_internal_link(&mut e1).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 2);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert!(e3.remove_internal_link(&mut e1).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 1);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert!(e2.remove_internal_link(&mut e1).is_ok());
assert_eq!(e1.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e2.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e3.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e4.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
assert_eq!(e5.get_internal_links().unwrap().collect::<Vec<_>>().len(), 0);
}
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}