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Commit 341735e

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sipasipa
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Headers-first synchronization
Many changes: * Do not use 'getblocks', but 'getheaders', and use it to build a headers tree. * Blocks are fetched in parallel from all available outbound peers, using a limited moving window. When one peer stalls the movement of the window, it is disconnected. * No more orphan blocks. At all. We only ever request a block for which we have verified the headers, and store it to disk immediately. This means that a disk-fill attack would require PoW. * Require protocol version 31800 for every peer (released in december 2010). * No more syncnode (we sync from everyone we can, though limited to 1 during initial *headers* sync). * Introduce some extra named constants, comments and asserts.
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9 files changed

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‎src/chain.h‎

Lines changed: 25 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -49,12 +49,29 @@ struct CDiskBlockPos
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};
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enum BlockStatus {
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// Unused.
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BLOCK_VALID_UNKNOWN = 0,
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BLOCK_VALID_HEADER = 1, // parsed, version ok, hash satisfies claimed PoW, 1 <= vtx count <= max, timestamp not in future
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BLOCK_VALID_TREE = 2, // parent found, difficulty matches, timestamp >= median previous, checkpoint
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BLOCK_VALID_TRANSACTIONS = 3, // only first tx is coinbase, 2 <= coinbase input script length <= 100, transactions valid, no duplicate txids, sigops, size, merkle root
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BLOCK_VALID_CHAIN = 4, // outputs do not overspend inputs, no double spends, coinbase output ok, immature coinbase spends, BIP30
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BLOCK_VALID_SCRIPTS = 5, // scripts/signatures ok
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// Parsed, version ok, hash satisfies claimed PoW, 1 <= vtx count <= max, timestamp not in future
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BLOCK_VALID_HEADER = 1,
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// All parent headers found, difficulty matches, timestamp >= median previous, checkpoint. Implies all parents
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// are also at least TREE.
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BLOCK_VALID_TREE = 2,
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// Only first tx is coinbase, 2 <= coinbase input script length <= 100, transactions valid, no duplicate txids,
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// sigops, size, merkle root. Implies all parents are at least TREE but not necessarily TRANSACTIONS. When all
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// parent blocks also have TRANSACTIONS, CBlockIndex::nChainTx will be set.
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BLOCK_VALID_TRANSACTIONS = 3,
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// Outputs do not overspend inputs, no double spends, coinbase output ok, immature coinbase spends, BIP30.
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// Implies all parents are also at least CHAIN.
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BLOCK_VALID_CHAIN = 4,
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// Scripts & signatures ok. Implies all parents are also at least SCRIPTS.
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BLOCK_VALID_SCRIPTS = 5,
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// All validity bits.
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BLOCK_VALID_MASK = BLOCK_VALID_HEADER | BLOCK_VALID_TREE | BLOCK_VALID_TRANSACTIONS |
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BLOCK_VALID_CHAIN | BLOCK_VALID_SCRIPTS,
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@@ -103,7 +120,8 @@ class CBlockIndex
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// Note: in a potential headers-first mode, this number cannot be relied upon
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unsigned int nTx;
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// (memory only) Number of transactions in the chain up to and including this block
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// (memory only) Number of transactions in the chain up to and including this block.
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// This value will be non-zero only if and only if transactions for this block and all its parents are available.
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unsigned int nChainTx; // change to 64-bit type when necessary; won't happen before 2030
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// Verification status of this block. See enum BlockStatus
@@ -146,7 +164,7 @@ class CBlockIndex
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SetNull();
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}
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149-
CBlockIndex(CBlockHeader& block)
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CBlockIndex(const CBlockHeader& block)
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{
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SetNull();
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