mirror of
https://github.com/hyperledger/fabric-samples.git
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69 lines
1.6 KiB
Go
69 lines
1.6 KiB
Go
/*
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Copyright 2020 IBM All Rights Reserved.
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SPDX-License-Identifier: Apache-2.0
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*/
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package functions
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import (
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"fmt"
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"os"
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"path/filepath"
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"github.com/hyperledger/fabric-sdk-go/pkg/core/config"
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"github.com/hyperledger/fabric-sdk-go/pkg/gateway"
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)
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// Query can be used to read the latest value of a variable
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func Query(function, variableName string) ([]byte, error) {
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err := os.Setenv("DISCOVERY_AS_LOCALHOST", "true")
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if err != nil {
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return nil, fmt.Errorf("error setting DISCOVERY_AS_LOCALHOST environemnt variable: %v", err)
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}
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wallet, err := gateway.NewFileSystemWallet("wallet")
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if err != nil {
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return nil, fmt.Errorf("failed to create wallet: %v", err)
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}
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if !wallet.Exists("appUser") {
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err = populateWallet(wallet)
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if err != nil {
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return nil, fmt.Errorf("failed to populate wallet contents: %v", err)
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}
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}
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ccpPath := filepath.Join(
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"..",
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"..",
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"test-network",
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"organizations",
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"peerOrganizations",
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"org1.example.com",
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"connection-org1.yaml",
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)
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gw, err := gateway.Connect(
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gateway.WithConfig(config.FromFile(filepath.Clean(ccpPath))),
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gateway.WithIdentity(wallet, "appUser"),
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)
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if err != nil {
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return nil, fmt.Errorf("failed to connect to gateway: %v", err)
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}
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defer gw.Close()
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network, err := gw.GetNetwork("mychannel")
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if err != nil {
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return nil, fmt.Errorf("failed to get network: %v", err)
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}
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contract := network.GetContract("bigdatacc")
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result, err := contract.EvaluateTransaction(function, variableName)
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if err != nil {
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return nil, fmt.Errorf("failed to evaluate transaction: %v", err)
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}
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return result, err
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}
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