datafeed

Oracle

0x65ede742c636...b7c3dc4e25fb

FrontierContract #1,014Exact Bytecode MatchEdit this contract

Deployed September 9, 2015 (10 years ago)Block 209,032

The datafeed example from the ethereum dapp-bin standardized contract APIs, a single owner key value oracle.

Frontier EraVerified Source

Context

Deployed 9 September 2015, during the Frontier era.

Key Facts

Deployer

0x7931c9...30ad34

Deployment Block

209,032

Deployment Date

Sep 9, 2015, 05:16 PM

Code Size

356.0 B

Gas at Deploy

120,095

Transactions by Year

20153

Deployment Transaction: 0x31472f6a9824ff44...5f282148f91de682

Description

The datafeed contract from the standardized contract APIs directory of the ethereum dapp-bin repository, one of the reference interfaces published so that early contracts could agree on how to read a price or a measurement from one another. The constructor records the deployer as owner. set takes a bytes32 key and a signed 256 bit value and writes it to storage when the caller is the owner; there is no else branch, so a call from anyone else succeeds and changes nothing. get returns the value stored under a key. get is declared as an ordinary function rather than a constant one, so a caller reading it through a transaction pays for the call even though it writes nothing.

Source Verified

Exact bytecode match(356 bytes)

Compiler: v0.1.1+

View verification proof

Heuristic Analysis

The following characteristics were detected through bytecode analysis and may not be accurate.

Detected Type: Oracle

Frontier Era

The initial release of Ethereum. A bare-bones implementation for technical users.

Block span: 0 — 1,149,999

July 30, 2015 — March 14, 2016

Bytecode Overview

Opcodes356

Unique Opcodes51

Jump Instructions11

Storage Operations6

Verified Source Available

Source verified through compiler archaeology and exact bytecode matching.

Verified on Etherscan

View Verification Proof

Show source code (Solidity)

// Submitted by EthereumHistory (ethereumhistory.com)
contract datafeed {
    mapping ( bytes32 => int256 ) data;
    address owner;

    function datafeed() {
        owner = msg.sender;
    }

    function set(bytes32 k, int256 v) {
        if (owner == msg.sender)
            data[k] = v;
    }

    function get(bytes32 k) returns (int256 v) {
        v = data[k];
    }
}

External Links

Etherscan Verified Source (if any)

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0xb5b8a0...9cfec6September 24, 2015