     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94

    // Copyright 2015-2017 Parity Technologies (UK) Ltd.
    // This file is part of Parity.

    // Parity is free software: you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation, either version 3 of the License, or
    // (at your option) any later version.

    // Parity 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 General Public License for more details.

    // You should have received a copy of the GNU General Public License
    // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

    use hash::H256;
    use sha3::Hashable;
    use hashdb::{HashDB, DBValue};
    use super::triedbmut::TrieDBMut;
    use super::TrieMut;

    /// A mutable `Trie` implementation which hashes keys and uses a generic `HashDB` backing database.
    ///
    /// Use it as a `Trie` or `TrieMut` trait object. You can use `raw()` to get the backing `TrieDBMut` object.
    pub struct SecTrieDBMut<'db> {
    	raw: TrieDBMut<'db>
    }

    impl<'db> SecTrieDBMut<'db> {
    	/// Create a new trie with the backing database `db` and empty `root`
    	/// Initialise to the state entailed by the genesis block.
    	/// This guarantees the trie is built correctly.
    	pub fn new(db: &'db mut HashDB, root: &'db mut H256) -> Self {
    		SecTrieDBMut { raw: TrieDBMut::new(db, root) }
    	}

    	/// Create a new trie with the backing database `db` and `root`.
    	///
    	/// Returns an error if root does not exist.
    	pub fn from_existing(db: &'db mut HashDB, root: &'db mut H256) -> super::Result<Self> {
    		Ok(SecTrieDBMut { raw: TrieDBMut::from_existing(db, root)? })
    	}

    	/// Get the backing database.
    	pub fn db(&self) -> &HashDB { self.raw.db() }

    	/// Get the backing database.
    	pub fn db_mut(&mut self) -> &mut HashDB { self.raw.db_mut() }
    }

    impl<'db> TrieMut for SecTrieDBMut<'db> {
    	fn root(&mut self) -> &H256 {
    		self.raw.root()
    	}

    	fn is_empty(&self) -> bool {
    		self.raw.is_empty()
    	}

    	fn contains(&self, key: &[u8]) -> super::Result<bool> {
    		self.raw.contains(&key.sha3())
    	}

    	fn get<'a, 'key>(&'a self, key: &'key [u8]) -> super::Result<Option<DBValue>>
    		where 'a: 'key
    	{
    		self.raw.get(&key.sha3())
    	}

    	fn insert(&mut self, key: &[u8], value: &[u8]) -> super::Result<Option<DBValue>> {
    		self.raw.insert(&key.sha3(), value)
    	}

    	fn remove(&mut self, key: &[u8]) -> super::Result<Option<DBValue>> {
    		self.raw.remove(&key.sha3())
    	}
    }

    #[test]
    fn sectrie_to_trie() {
    	use memorydb::*;
    	use super::triedb::*;
    	use super::Trie;

    	let mut memdb = MemoryDB::new();
    	let mut root = H256::default();
    	{
    		let mut t = SecTrieDBMut::new(&mut memdb, &mut root);
    		t.insert(&[0x01u8, 0x23], &[0x01u8, 0x23]).unwrap();
    	}
    	let t = TrieDB::new(&memdb, &root).unwrap();
    	assert_eq!(t.get(&(&[0x01u8, 0x23]).sha3()).unwrap().unwrap(), DBValue::from_slice(&[0x01u8, 0x23]));
    }

# Help

## Keyboard Shortcuts

?
  Show this help dialog
S
  Focus the search field
⇤
  Move up in search results
⇥
  Move down in search results
⏎
  Go to active search result
+
  Collapse/expand all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)