Hypertable::ClusterDefinitionFile::TranslatorTask Class Reference

Translates a task definition. More...

#include <TranslatorTask.h>

Inheritance diagram for Hypertable::ClusterDefinitionFile::TranslatorTask:

Collaboration diagram for Hypertable::ClusterDefinitionFile::TranslatorTask:

Public Member Functions
	TranslatorTask (const string &fname, size_t lineno, const string &text)
	Constructor. More...
const string	translate (TranslationContext &context) override
	Translates a task definition. More...

Private Attributes
string	m_fname
	Source file name containing task definition. More...
size_t	m_lineno
	Line number within m_fname of task definition. More...
string	m_text
	Text of task definition. More...

Detailed Description

Translates a task definition.

Definition at line 43 of file TranslatorTask.h.

Constructor & Destructor Documentation

Hypertable::ClusterDefinitionFile::TranslatorTask::TranslatorTask ( const string &  fname, size_t  lineno, const string &  text  )

inline

Constructor.

Parameters

fname	Filename of source file containing task definition
lineno	Line number within source file of task definition
text	Text of task definition

Definition at line 49 of file TranslatorTask.h.

Member Function Documentation

const string TranslatorTask::translate ( TranslationContext &  context )

overridevirtual

Translates a task definition.

The best way to illustrate how tasks get translated is with an example. The following task definition:

  task: display_hostnames roles: master,slave {
    echo "before"
    ssh: {
      hostname
    }
    echo "after"
  }

gets translated into a bash function similar to the following:

  display_hostnames () {
    local _SSH_HOSTS="(${ROLE_master}) + (${ROLE_slave})"
    if [ $# -gt 0 ] && [ $1 == "on" ]; then
      shift
      if [ $# -eq 0 ]; then
        echo "Missing host specification in 'on' argument"
        exit 1
      else
        _SSH_HOSTS="$1"
        shift
      fi
    fi
    echo "display_hostnames $@"
    echo "before"
    /opt/hypertable/0.9.8.1/bin/ht ssh " ${_SSH_HOSTS}" "hostname"
    echo "after"
  }

Notice that the ssh: statemnts get translated to a call to the ht_ssh tool. Also, the function includes logic to check for on <hostspec> initial arguments. If found, the target hosts for ssh: statements becomes <hostspec> instead of the default roles specified by the roles: clause.

Parameters

context

Context object containing symbol tables

Returns

translated task statement

Implements Hypertable::ClusterDefinitionFile::Translator.

Definition at line 157 of file TranslatorTask.cc.

Member Data Documentation

string Hypertable::ClusterDefinitionFile::TranslatorTask::m_fname

private

Source file name containing task definition.

Definition at line 96 of file TranslatorTask.h.

size_t Hypertable::ClusterDefinitionFile::TranslatorTask::m_lineno

private

Line number within m_fname of task definition.

Definition at line 98 of file TranslatorTask.h.

string Hypertable::ClusterDefinitionFile::TranslatorTask::m_text

private

Text of task definition.

Definition at line 100 of file TranslatorTask.h.

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The documentation for this class was generated from the following files:

• /home/doug/src/hypertable/src/cc/Common/ClusterDefinitionFile/TranslatorTask.h
• /home/doug/src/hypertable/src/cc/Common/ClusterDefinitionFile/TranslatorTask.cc