      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
     95
     96
     97
     98
     99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198

    // 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/>.

    //! Definition of valid items for the verification queue.

    use engines::Engine;
    use error::Error;

    use util::{HeapSizeOf, H256, U256};

    pub use self::blocks::Blocks;
    pub use self::headers::Headers;

    /// Something which can produce a hash and a parent hash.
    pub trait BlockLike {
    	/// Get the hash of this item.
    	fn hash(&self) -> H256;

    	/// Get the hash of this item's parent.
    	fn parent_hash(&self) -> H256;

    	/// Get the difficulty of this item.
    	fn difficulty(&self) -> U256;
    }

    /// Defines transitions between stages of verification.
    ///
    /// It starts with a fallible transformation from an "input" into the unverified item.
    /// This consists of quick, simply done checks as well as extracting particular data.
    ///
    /// Then, there is a `verify` function which performs more expensive checks and
    /// produces the verified output.
    ///
    /// For correctness, the hashes produced by each stage of the pipeline should be
    /// consistent.
    pub trait Kind: 'static + Sized + Send + Sync {
    	/// The first stage: completely unverified.
    	type Input: Sized + Send + BlockLike + HeapSizeOf;

    	/// The second stage: partially verified.
    	type Unverified: Sized + Send + BlockLike + HeapSizeOf;

    	/// The third stage: completely verified.
    	type Verified: Sized + Send + BlockLike + HeapSizeOf;

    	/// Attempt to create the `Unverified` item from the input.
    	fn create(input: Self::Input, engine: &Engine) -> Result<Self::Unverified, Error>;

    	/// Attempt to verify the `Unverified` item using the given engine.
    	fn verify(unverified: Self::Unverified, engine: &Engine, check_seal: bool) -> Result<Self::Verified, Error>;
    }

    /// The blocks verification module.
    pub mod blocks {
    	use super::{Kind, BlockLike};

    	use engines::Engine;
    	use error::Error;
    	use header::Header;
    	use verification::{PreverifiedBlock, verify_block_basic, verify_block_unordered};

    	use util::{Bytes, HeapSizeOf, H256, U256};

    	/// A mode for verifying blocks.
    	pub struct Blocks;

    	impl Kind for Blocks {
    		type Input = Unverified;
    		type Unverified = Unverified;
    		type Verified = PreverifiedBlock;

    		fn create(input: Self::Input, engine: &Engine) -> Result<Self::Unverified, Error> {
    			match verify_block_basic(&input.header, &input.bytes, engine) {
    				Ok(()) => Ok(input),
    				Err(e) => {
    					warn!(target: "client", "Stage 1 block verification failed for {}: {:?}", input.hash(), e);
    					Err(e)
    				}
    			}
    		}

    		fn verify(un: Self::Unverified, engine: &Engine, check_seal: bool) -> Result<Self::Verified, Error> {
    			let hash = un.hash();
    			match verify_block_unordered(un.header, un.bytes, engine, check_seal) {
    				Ok(verified) => Ok(verified),
    				Err(e) => {
    					warn!(target: "client", "Stage 2 block verification failed for {}: {:?}", hash, e);
    					Err(e)
    				}
    			}
    		}
    	}

    	/// An unverified block.
    	pub struct Unverified {
    		header: Header,
    		bytes: Bytes,
    	}

    	impl Unverified {
    		/// Create an `Unverified` from raw bytes.
    		pub fn new(bytes: Bytes) -> Self {
    			use views::BlockView;

    			let header = BlockView::new(&bytes).header();
    			Unverified {
    				header: header,
    				bytes: bytes,
    			}
    		}
    	}

    	impl HeapSizeOf for Unverified {
    		fn heap_size_of_children(&self) -> usize {
    			self.header.heap_size_of_children() + self.bytes.heap_size_of_children()
    		}
    	}

    	impl BlockLike for Unverified {
    		fn hash(&self) -> H256 {
    			self.header.hash()
    		}

    		fn parent_hash(&self) -> H256 {
    			self.header.parent_hash().clone()
    		}

    		fn difficulty(&self) -> U256 {
    			self.header.difficulty().clone()
    		}
    	}

    	impl BlockLike for PreverifiedBlock {
    		fn hash(&self) -> H256 {
    			self.header.hash()
    		}

    		fn parent_hash(&self) -> H256 {
    			self.header.parent_hash().clone()
    		}

    		fn difficulty(&self) -> U256 {
    			self.header.difficulty().clone()
    		}
    	}
    }

    /// Verification for headers.
    pub mod headers {
    	use super::{Kind, BlockLike};

    	use engines::Engine;
    	use error::Error;
    	use header::Header;
    	use verification::verify_header_params;

    	use util::hash::H256;
    	use util::U256;

    	impl BlockLike for Header {
    		fn hash(&self) -> H256 { self.hash() }
    		fn parent_hash(&self) -> H256 { self.parent_hash().clone() }
    		fn difficulty(&self) -> U256 { self.difficulty().clone() }
    	}

    	/// A mode for verifying headers.
    	pub struct Headers;

    	impl Kind for Headers {
    		type Input = Header;
    		type Unverified = Header;
    		type Verified = Header;

    		fn create(input: Self::Input, engine: &Engine) -> Result<Self::Unverified, Error> {
    			verify_header_params(&input, engine).map(|_| input)
    		}

    		fn verify(unverified: Self::Unverified, engine: &Engine, check_seal: bool) -> Result<Self::Verified, Error> {
    			match check_seal {
    				true => engine.verify_block_unordered(&unverified, None).map(|_| unverified),
    				false => Ok(unverified),
    			}
    		}
    	}
    }

# 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`)