write-fact

README

write-fact

Utility tool to write facts to passport.

Usage

Usage of ./write-fact:

  -backendurl string
    	backend URL (simulated backend used if empty)
  -fkey string
    	the key of the fact (max. 32 bytes)
  -ftype string
    	the data type of fact (txdata, string, bytes, address, uint, int, bool, ipfs)
  -ipfsurl string
    	IPFS node address (default "https://ipfs.infura.io:5001")
  -ownerkey string
    	fact provider private key filename
  -ownerkeyhex string
    	fact provider private key as hex (for testing)
  -passportaddr value
    	Ethereum address of passport contract
  -verbosity int
    	log verbosity (0-9) (default 2)
  -vmodule string
    	log verbosity pattern

Gas usage

Cumulative gas usage in simulated backend to store number of character of a under the key aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa using different data types:

Number of characters	ipfs, gas used	txdata, gas used	bytes, gas used	string, gas used
10	114245	70436	71079	71211
100	114245	76598	157571	157703
500	114245	103870	425756	425888
1000	114245	138016	781119	781251
5000	114245	410814	3563467	3563599
10000	114245	751864	7036521	7036653
50000	114245	3483963	-	-
100000	114245	6907662	-	-
110000	114245	7593621	-	-
120000	114245	8279814	-	-
130000	114245	8966537	-	-

Examples

• Store 1000 characters of a under the key aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa as txdata in simulated backend using fact provider private key 1dae9ab9e0c080371c56d816f4b6323e6c229e1cea4d15bc7f828c40ad9729d6:

  head -c 1000 < /dev/zero | tr '\0' '\141' | ./write-fact \
    -fkey aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \
    -ftype txdata \
    -ownerkeyhex 1dae9ab9e0c080371c56d816f4b6323e6c229e1cea4d15bc7f828c40ad9729d6
  

• Store image from the file ~/Downloads/monetha.jpg under the key monetha.jpg as txdata in passport 0x9CfabB3172DFd5ED740c3b8A327BF573226c5064:

  ./write-fact -ownerkey fact_provider.key \
    -fkey monetha.jpg \
    -ftype txdata \
    -passportaddr 0x9CfabB3172DFd5ED740c3b8A327BF573226c5064 \
    -backendurl https://ropsten.infura.io < ~/Downloads/monetha.jpg
  

• Store image from the file ~/Downloads/monetha.jpg under the key monetha.jpg as ipfs (data will be stored in IPFS, only hash will be stored in the Ethereum storage) in passport 0x9CfabB3172DFd5ED740c3b8A327BF573226c5064:

  ./write-fact -ownerkey fact_provider.key \
    -fkey monetha.jpg \
    -ftype ipfs \
    -passportaddr 0x9CfabB3172DFd5ED740c3b8A327BF573226c5064 \
    -backendurl https://ropsten.infura.io < ~/Downloads/monetha.jpg