Interview assignment for bloxroute.
- Parse a file formatted according to bitcoin protocol (clarification: the sample file only had a block message, so that's what I am doing here)
- The relevant bitcoin protocol can be found here (https://en.bitcoin.it/wiki/Protocol_documentation)
- Extract the 100 longest transactions in the block (clarification: by size of transaction data, not by length of transaction chain)
- Create data structure(s) that will allow:
- Iteration on the data structure(s) based on the transaction length
- Lookup a transaction by its hash value and return if it in the 100 longest transactions
- For each transaction you should save the following:
- Sequence position in the block
- Transaction hash value
- Length, Starting offset and Ending offset
A command line program that does it.
build it with make (Makefile incldued). Requires gcc and presense of openssl library. Works on Ubuntu 18.4.2 LTS; used gcc 7.4.0
./program -h
./program [-h|-f <file_name> [-l | -s <hash>]]
-h print help message
-f <file> parse file with bitcoin protocol messages
-l list all hunded longest transactions
-s <hash> lookup entry by hash
-t print traces
Example usage:
Find a transaction by hash in the list of 100 longest transaction and print it:
./program -f sample_block_bin -s d483d48decfa82509f4dd070b05010f589efcaebc95016e2f1ec56a328cf67bd
lookup of hash=d483d48decfa82509f4dd070b05010f589efcaebc95016e2f1ec56a328cf67bd
lookup of hash=d483d48decfa82509f4dd070b05010f589efcaebc95016e2f1ec56a328cf67bd
found entry!
block_index=0 tx_index=30760 start_pos=6930429 end_pos=6930655 length=226 hash=d483d48decfa82509f4dd070b05010f589efcaebc95016e2f1ec56a328cf67bd
List the 100 longest transactions
./program -f sample_block_bin -l
block_index=0 tx_index=30812 start_pos=6942172 end_pos=6942398 length=226 hash=d3b53fa254d25d1515ac508a11e40850ad87b8e2bbe7e6b18f6ce01035b51a27
block_index=0 tx_index=30811 start_pos=6941946 end_pos=6942172 length=226 hash=d3b6c19db83c663b245bf786b59681074add06d24d170c95b51702a940d5d21f
block_index=0 tx_index=30833 start_pos=6946910 end_pos=6947136 length=226 hash=d37034d89642c8c3360f3f255df509561209bb047904543d4f28865b09c3ae53
block_index=0 tx_index=30809 start_pos=6941494 end_pos=6941720 length=226 hash=d3bb50037f20d02a054ea3ff9b89e723e1b8e28121a0be45cd71dd0aa333d290
block_index=0 tx_index=30808 start_pos=6941268 end_pos=6941494 length=226 hash=d3bfea499ca8243e75e601d28331b13575646f6967a4dfb232c7dbe8d7a7cfa5
block_index=0 tx_index=30807 start_pos=6941042 end_pos=6941268 length=226 hash=e8b92cd54150f45389aa7bae7e2966f0d92abf346b390298b00da4e83a3d05e9
....
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