重要操作

看起来很复杂，但我们可以用排除法，先将如下和数方法进行筛选：数据查询、检查判断、逻辑判断、可重复操作，剩下各个方法才是我们的重点关注对象。

init

    /// Initializes the blockchain and returns a new Chain instance. Does a
    /// check on the current chain head to make sure it exists and creates one
    /// based on the genesis block if necessary.

process_block

    /// Processes a single block, then checks for orphans, processing
    /// those as well if they're found

process_block_single

    /// Attempt to add a new block to the chain.
    /// Returns true if it has been added to the longest chain
    /// or false if it has added to a fork (or orphan?).

process_block_no_orphans

    /// Attempt to add a new block to the chain. Returns the new chain tip if it
    /// has been added to the longest chain, None if it's added to an (as of
    /// now) orphan chain.

process_block_header

/// Process a block header received during "header first" propagation.

validate

    /// Validate the current chain state.

txhashset_read

    /// Provides a reading view into the current txhashset state as well as
    /// the required indexes for a consumer to rewind to a consistent state
    /// at the provided block hash.

txhashset_write

    /// Writes a reading view on a txhashset state that's been provided to us.
    /// If we're willing to accept that new state, the data stream will be
    /// read as a zip file, unzipped and the resulting state files should be
    /// rewound to the provided indexes.

其它操作也很重要，只是篇幅有限，这里挑几个出来讲解。

compact

    /// Triggers chain compaction, cleaning up some unnecessary historical
    /// information. We introduce a chain depth called horizon, which is
    /// typically in the range of a couple days. Before that horizon, this
    /// method will:
    ///
    /// * compact the MMRs data files and flushing the corresponding remove logs
    /// * delete old records from the k/v store (older blocks, indexes, etc.)
    ///
    /// This operation can be resource intensive and takes some time to execute.
    /// Meanwhile, the chain will not be able to accept new blocks. It should
    /// therefore be called judiciously.

get_last_n_output

/// returns the last n nodes inserted into the output sum tree

get_last_n_rangeproof

/// as above, for rangeproofs

get_last_n_kernel

/// as above, for kernels

unspent_outputs_by_insertion_index

/// outputs by insertion index

total_difficulty

/// Total difficulty at the head of the chain

orphans_len

/// Orphans pool size

total_header_difficulty

/// Total difficulty at the head of the header chain

reset_head

/// Reset header_head and sync_head to head of current body chain

head

/// Get the tip that's also the head of the chain

head_header

/// Block header for the chain head

get_block

/// Gets a block header by hash

get_block_header

/// Gets a block header by hash

get_header_by_height

/// Gets the block header at the provided height

is_on_current_chain

    /// Verifies the given block header is actually on the current chain.
    /// Checks the header_by_height index to verify the header is where we say
    /// it is

get_sync_head

    /// Get the tip of the current "sync" header chain.
    /// This may be significantly different to current header chain.

get_header_head

/// Get the tip of the header chain.

difficulty_iter

    /// Builds an iterator on blocks starting from the current chain head and
    /// running backward. Specialized to return information pertaining to block
    /// difficulty calculation (timestamp and previous difficulties).

block_exists

/// Check whether we have a block without reading it

is_unspent

    /// For the given commitment find the unspent output and return the
    /// associated Return an error if the output does not exist or has been
    /// spent. This querying is done in a way that is consistent with the
    /// current chain state, specifically the current winning (valid, most
    /// work) fork.

block_exists

/// Check whether we have a block without reading it