isclib.go

/*
Copyright 2016 Ontario Systems

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

/*
Package isclib facilitates managing and interacting with ISC products

A simple example of checking for available ISC commands

	package main

	import (
	    "github.com/ontariosystems/isclib/v2"
	)

	func main() {
	    if isclib.AvailableCommands().Has(isclib.CControlCommand) {
	        // perform actions if Cache/Ensemble is installed
	    }

	    if isclib.AvailableCommands().Has(isclib.IrisCommand) {
	        //perform actions if Iris is installed
	    }
	}

You can get access to an instance, find information about the instance (installation directory, status, ports, version, etc.) and perform operations like starting/stopping the instance and executing code in a namespace

A simple example of interacting with an instance by ensuring the instance is running and then printing the version

		package main

		import (
			"bytes"
			"fmt"

			"github.com/ontariosystems/isclib/v2"
		)

		const (
			c = `MAIN
	 	write $zversion
	 	do $system.Process.Terminate($job,0)
	 	quit

		`
		)

		func main() {
			i, err := isclib.LoadInstance("docker")
			if err != nil {
				panic(err)
			}

			if i.Status == "down" {
				if err := i.Start(); err != nil {
					panic(err)
				}
			}

			r := bytes.NewReader([]byte(c))
			if out, err := i.Execute("%SYS", r); err != nil {
				panic(err)
			} else {
				fmt.Println(out)
			}
		}
*/
package isclib

// TODO: Consider making a pass through this entire library and using fmt.Errorf to wrap errors where appropriate

import (
	"bufio"
	"bytes"
	"fmt"
)

const (
	defaultCControlPath = "ccontrol"
	defaultIrisPath     = "iris"
	defaultCSessionPath = "csession"
	iscParametersFile   = "parameters.isc"
)

const (
	importXMLHeader = `<?xml version="1.0" encoding="UTF-8"?>
<Export generator="Cache" version="25">
<Routine name="%s" type="MAC" languagemode="0"><![CDATA[
EnsLibMain() public {
	try {
		do MAIN
	} catch ex {
		do BACK^%%ETN
		use 0
		write !,"Exception: ",ex.DisplayString(),!,"  name: ",ex.Name,!,"  code: ",ex.Code,!
		do $zutil(4, $job, 99)
	}
}

`
	importXMLFooter = `
]]></Routine>
</Export>`
)

var (
	globalCControlPath        = defaultCControlPath
	globalIrisPath            = defaultIrisPath
	globalCSessionPath        = defaultCSessionPath
	globalIrisSessionCommand  = fmt.Sprintf("%s session", defaultIrisPath)
	executeTemporaryDirectory = "" // Default is system temp directory
)

// CControlPath returns the current path to the ccontrol executable
func CControlPath() string { return globalCControlPath }

// SetCControlPath sets the current path to the ccontrol executable
func SetCControlPath(path string) {
	globalCControlPath = path
}

// IrisPath returns the current path to the iris executable
func IrisPath() string { return globalIrisPath }

// SetIrisPath sets the current path to the iris executable
func SetIrisPath(path string) {
	globalIrisPath = path
}

// CSessionPath returns the current path to the csession executable
func CSessionPath() string { return globalCSessionPath }

// SetCSessionPath sets the current path to the csession executable
func SetCSessionPath(path string) {
	globalCSessionPath = path
}

// IrisSessionCommand returns the current string for the iris session command
func IrisSessionCommand() string { return globalIrisSessionCommand }

// SetIrisSessionCommand sets the current string for the iris session command
func SetIrisSessionCommand(path string) {
	globalIrisSessionCommand = path
}

// ExecuteTemporaryDirectory returns the directory where temporary files for ObjectScript execution will be placed.
// "" means the system default temp directory.
func ExecuteTemporaryDirectory() string {
	return executeTemporaryDirectory
}

// SetExecuteTemporaryDirectory sets the directory where temporary files for ObjectScript execution will be placed.
// Passing "" will result in using the system default temp directory.
func SetExecuteTemporaryDirectory(path string) {
	executeTemporaryDirectory = path
}

// LoadInstances returns a listing of all Caché/Ensemble instances on this system.
// It returns the list of instances and any error encountered.
func LoadInstances() (Instances, error) {
	qs, err := qlist("", nil)
	if err != nil {
		return nil, err
	}

	instances := make(Instances, 0)
	scanner := bufio.NewScanner(bytes.NewBufferString(qs))
	for scanner.Scan() {
		instance, err := InstanceFromQList(scanner.Text())
		if err != nil {
			return nil, err
		}

		instances = append(instances, instance)
	}

	if err := scanner.Err(); err != nil {
		return nil, err
	}

	return instances, nil
}

// LoadInstance retrieves a single instance by name.
// The instance name is case-insensitive.
// It returns the instance and any error encountered.
func LoadInstance(name string) (*Instance, error) {
	i := &Instance{Name: name}
	if err := i.Update(); err != nil {
		return nil, err
	}

	return i, nil
}

// InstanceFromQList will parse the output of a qlist into an Instance struct.
// It expects the results of a qlist for a single instance as a string.
// It returns the parsed instance and any error encountered.
func InstanceFromQList(qlist string) (*Instance, error) {
	i := new(Instance)
	if err := i.UpdateFromQList(qlist); err != nil {
		return nil, err
	}

	// if the status is unknown, we may be running as a different user,
	// do the full update (running qlist again as the correct user)
	if i.Status == InstanceStatusUnknown {
		if err := i.Update(); err != nil {
			return nil, err
		}
	}

	return i, nil
}