31 lines
1.2 KiB
Markdown
31 lines
1.2 KiB
Markdown
## Functionality
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### Head syncer
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Opens a websocket connection and processes live transactions.
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### Janitor
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Periodically checks for missed (and historical) blocks missed by the head syncer and queues them for processing. A gap range is processed twice to guarantee there is no missing block.
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### Pipeline
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Fetches a block and executes the filters in serial order for every transaction in the block before finally committing the block to the store.
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### Filter
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Processes a transaction and passes it on to the next filter or terminates the pipeline for that transaction if it is irrelevant.
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### Store schema
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- The `blocks` table keeps track of processed blocks.
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- The `syncer_meta` table keeps track of the lower_bound cursor. Below the lower_bound cursor, all blocks are guarnteed to have been processsed hence it is safe to trim the `blocks` table below that pointer.
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### GraphQL
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- Fetches a block (and some of its header details), transactions and transaction receipts embedded within the transaction object in a single call.
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## Caveats
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- Blocks are not guaranteed to be processed in order, however a low concurrency setting would somewhat give an "in-order" behaviour (not to be relied upon in any case).
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