Add default generators

4 files changed, 335 insertions, 0 deletions

diff --git a/lib/entry/libimagentryref/Cargo.toml b/lib/entry/libimagentryref/Cargo.toml
index 5e1f7f9a..46178af7 100644
--- a/lib/entry/libimagentryref/Cargo.toml
+++ b/lib/entry/libimagentryref/Cargo.toml
@@ -30,3 +30,18 @@ libimagstore     = { version = "0.7.0", path = "../../../lib/core/libimagstore"
 libimagerror     = { version = "0.7.0", path = "../../../lib/core/libimagerror" }
 libimagentrylist = { version = "0.7.0", path = "../../../lib/entry/libimagentrylist" }
 libimagentryutil = { version = "0.7.0", path = "../../../lib/entry/libimagentryutil" }
+
+[dependencies.rust-crypto]
+version = "0.2"
+optional = true
+
+[features]
+default             = []
+generators          = []
+generators-sha1     = ["rust-crypto"]
+generators-sha224   = ["rust-crypto"]
+generators-sha256   = ["rust-crypto"]
+generators-sha384   = ["rust-crypto"]
+generators-sha512   = ["rust-crypto"]
+generators-sha3     = ["rust-crypto"]
+
diff --git a/lib/entry/libimagentryref/src/generators/base.rs b/lib/entry/libimagentryref/src/generators/base.rs
new file mode 100644
index 00000000..aea60b28
--- /dev/null
+++ b/lib/entry/libimagentryref/src/generators/base.rs
@@ -0,0 +1,48 @@
+//
+// 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 std::path::Path;
+
+use libimagstore::storeid::StoreId;
+
+use error::RefError;
+use refstore::UniqueRefPathGenerator;
+
+/// A base UniqueRefPathGenerator which must be overridden by the actual UniqueRefPathGenerator
+/// which is provided by this crate
+#[allow(dead_code)]
+pub struct Base;
+
+impl UniqueRefPathGenerator for Base {
+    type Error = RefError;
+
+    fn collection() -> &'static str {
+        "ref"
+    }
+
+    fn unique_hash<A: AsRef<Path>>(_path: A) -> Result<String, Self::Error> {
+        // This has to be overridden
+        panic!("Not overridden base functionality. This is a BUG!")
+    }
+
+    fn postprocess_storeid(sid: StoreId) -> Result<StoreId, Self::Error> {
+        Ok(sid) // default implementation
+    }
+}
+
diff --git a/lib/entry/libimagentryref/src/generators/mod.rs b/lib/entry/libimagentryref/src/generators/mod.rs
new file mode 100644
index 00000000..730fd640
--- /dev/null
+++ b/lib/entry/libimagentryref/src/generators/mod.rs
@@ -0,0 +1,259 @@
+//
+// 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
+//
+
+//! Default generators
+//!
+//! This module provides a number of default `UniqueRefPathGenerator`s
+//! which can be used for generating references.
+//!
+//! These generators are _NOT_ domain specific. So there won't be a "UniqueMailRefPathGenerator" in
+//! here, for example.
+//!
+//! All these generators use "ref" as collection name.
+//! They can be overridden using the `make_unique_ref_path_generator!()` convenience macro.
+//!
+//! # Note
+//!
+//! You must enable the appropriate crate feature to use any of the provided generators. With the
+//! `generators` feature, you only get the convenience macro `make_unique_ref_path_generator!()`.
+//!
+
+/// A convenience macro for wrapping a generator in a new one, reusing the functionality from the
+/// underlying generator
+///
+/// The UniqueRefPathGenerator must be in scope.
+///
+/// The macro creates a new struct `$name` over `$underlying` and changes the collection name to
+/// `$collectionname`.
+/// If passed, the new implementation is used (defaults to the implementation from the underlying
+/// generator).
+/// If passed, the new postprocessing is used (defaults to not changing the StoreId)
+///
+#[macro_export]
+macro_rules! make_unique_ref_path_generator {
+    (
+        $name:ident
+        over $underlying:ty
+        => with error $errtype:ty
+        => with collection name $collectionname:expr
+    ) => {
+        struct $name;
+        impl_unique_ref_path_generator_trait!(
+            $name
+            over $underlying
+            => with error $errtype
+            => with collection name  $collectionname
+            => |p| { $underlying::unique_hash(p) } => |s| { Ok(s) }
+            );
+    };
+
+    (
+        $name:ident
+        over $underlying:ty
+        => with error $errtype:ty
+        => with collection name $collectionname:expr
+        => $impl:expr
+    ) => {
+        struct $name;
+        impl_unique_ref_path_generator_trait!(
+            $name
+            over $underlying
+            => with error $errtype
+            => with collection name $collectionname
+            => $impl => |sid| { Ok(sid) }
+            );
+    };
+
+    (
+        pub $name:ident
+        over $underlying:ty
+        => with error $errtype:ty
+        => with collection name $collectionname:expr
+        => $impl:expr
+    ) => {
+        make_unique_ref_path_generator!(
+            pub $name
+            over $underlying
+            => with error $errtype
+            => with collection name $collectionname
+            => $impl => |sid| { Ok(sid) }
+            );
+    };
+
+    (
+        pub $name:ident
+        over $underlying:ty
+        => with error $errtype:ty
+        => with collection name $collectionname:expr
+        => $impl:expr
+        => $postproc:expr
+    ) => {
+        pub struct $name;
+        impl_unique_ref_path_generator_trait!(
+            $name, $underlying, $errtype, $collectionname => $impl => $postproc
+            );
+    };
+}
+
+macro_rules! impl_unique_ref_path_generator_trait {
+    ($name:ident, $underlying:ty, $errtype:ty, $collectionname:expr => $impl:expr => $postproc:expr) => {
+        impl $crate::refstore::UniqueRefPathGenerator for $name {
+            type Error = $errtype;
+
+            fn collection() -> &'static str {
+                $collectionname
+            }
+
+            fn unique_hash<A: AsRef<Path>>(path: A) -> Result<String, Self::Error> {
+                $impl(path)
+            }
+
+            fn postprocess_storeid(sid: ::libimagstore::storeid::StoreId)
+                -> Result<::libimagstore::storeid::StoreId, Self::Error>
+            {
+                $postproc(sid)
+            }
+        }
+    }
+}
+
+
+#[cfg(any(
+        feature = "generators-sha1",
+        feature = "generators-sha224",
+        feature = "generators-sha256",
+        feature = "generators-sha384",
+        feature = "generators-sha512",
+        feature = "generators-sha3",
+        ))]
+mod base;
+
+/// Helper macro for generating implementations for the various Sha algorithms
+macro_rules! make_sha_mod {
+    {
+        $modname:ident,
+        $hashname:ident,
+        $hashingimpl:expr
+    } => {
+        pub mod $modname {
+            use std::path::Path;
+            use std::fs::OpenOptions;
+            use std::io::Read;
+
+            use error::RefError as RE;
+
+            use crypto::digest::Digest;
+            make_unique_ref_path_generator! (
+                pub $hashname
+                over generators::base::Base
+                => with error RE
+                => with collection name "ref"
+                => |path| {
+                    OpenOptions::new()
+                        .read(true)
+                        .write(false)
+                        .create(false)
+                        .open(path)
+                        .map_err(RE::from)
+                        .and_then(|mut file| {
+                            let mut buffer = String::new();
+                            let _ = file.read_to_string(&mut buffer)?;
+                            $hashingimpl(buffer)
+                        })
+                }
+            );
+
+            impl $hashname {
+
+                /// Function which can be used by a wrapping UniqueRefPathGenerator to hash only N bytes.
+                pub fn hash_n_bytes<A: AsRef<Path>>(path: A, n: usize) -> Result<String, RE> {
+                    OpenOptions::new()
+                        .read(true)
+                        .write(false)
+                        .create(false)
+                        .open(path)
+                        .map_err(RE::from)
+                        .and_then(|mut file| {
+                            let mut buffer = Vec::with_capacity(n);
+                            let _ = file.read_exact(&mut buffer)?;
+                            let buffer = String::from_utf8(buffer)?;
+                            $hashingimpl(buffer)
+                        })
+                }
+
+            }
+
+        }
+    }
+}
+
+#[cfg(feature = "generators-sha1")]
+make_sha_mod! {
+    sha1, Sha1, |buffer: String| {
+        let mut hasher = ::crypto::sha1::Sha1::new();
+        hasher.input_str(&buffer);
+        Ok(String::from(hasher.result_str()))
+    }
+}
+
+#[cfg(feature = "generators-sha224")]
+make_sha_mod! {
+    sha224, Sha224, |buffer: String| {
+        let mut hasher = ::crypto::sha2::Sha224::new();
+        hasher.input_str(&buffer);
+        Ok(String::from(hasher.result_str()))
+    }
+}
+
+#[cfg(feature = "generators-sha256")]
+make_sha_mod! {
+    sha256, Sha256, |buffer: String| {
+        let mut hasher = ::crypto::sha2::Sha256::new();
+        hasher.input_str(&buffer);
+        Ok(String::from(hasher.result_str()))
+    }
+}
+
+#[cfg(feature = "generators-sha384")]
+make_sha_mod! {
+    sha384, Sha384, |buffer: String| {
+        let mut hasher = ::crypto::sha2::Sha384::new();
+        hasher.input_str(&buffer);
+        Ok(String::from(hasher.result_str()))
+    }
+}
+
+#[cfg(feature = "generators-sha512")]
+make_sha_mod! {
+    sha512, Sha512, |buffer: String| {
+        let mut hasher = ::crypto::sha2::Sha512::new();
+        hasher.input_str(&buffer);
+        Ok(String::from(hasher.result_str()))
+    }
+}
+
+#[cfg(feature = "generators-sha3")]
+make_sha_mod! {
+    sha3, Sha3, |buffer: String| {
+        let mut hasher = ::crypto::sha3::Sha3::sha3_256();
+        hasher.input_str(&buffer);
+        Ok(String::from(hasher.result_str()))
+    }
+}
+
diff --git a/lib/entry/libimagentryref/src/lib.rs b/lib/entry/libimagentryref/src/lib.rs
index 7311d13b..39f3c546 100644
--- a/lib/entry/libimagentryref/src/lib.rs
+++ b/lib/entry/libimagentryref/src/lib.rs
@@ -52,3 +52,16 @@ pub mod error;
 pub mod reference;
 pub mod refstore;
 
+#[cfg(any(
+    feature = "generators-sha1",
+    feature = "generators-sha224",
+    feature = "generators-sha256",
+    feature = "generators-sha384",
+    feature = "generators-sha512",
+    feature = "generators-sha3",
+))]
+extern crate crypto;
+
+#[cfg(feature = "generators")]
+pub mod generators;
+