Hypertable::ClusterDefinitionFile::Compiler Class Reference

Compiles a cluster definition file into an executable bash script. More...

#include <Compiler.h>

Collaboration diagram for Hypertable::ClusterDefinitionFile::Compiler:

Public Member Functions
	Compiler (const string &fname)
	Constructor. More...
string	output_script ()
	Returns pathname of output script. More...

Private Member Functions
bool	compilation_needed ()
	Determines if script needs to be re-built. More...
void	make ()
	Compiles the definition file into a task execution script. More...

Private Attributes
string	m_definition_file
	Cluster definition file. More...
string	m_output_script
	Output script. More...

Detailed Description

Compiles a cluster definition file into an executable bash script.

Definition at line 45 of file Compiler.h.

Constructor & Destructor Documentation

Compiler::Compiler

(

const string &

fname

)

Constructor.

Initializes m_definition_file with fname and initializes m_output_script with the pathname of the output script constructed as follows:

${HOME} + "/.cluster/" + m_definition_file + ".sh"

It then calls compilation_needed() to determine if the script needs to be rebuilt and, if so, calls make().

Parameters

fname

Pathname of cluster definition file

Definition at line 154 of file Compiler.cc.

Member Function Documentation

bool Compiler::compilation_needed ( )

private

Determines if script needs to be re-built.

This function returns true if 1) the output script (m_output_script) does not exist, or 2) the modification timestamp of the definition file (m_definition_file) or any of its dependencies (included files) is greater than the modification timestamp of the output script, or 3) The Hypertable version string listed in the comment header of the output script does not match the current Hypertable version string. The dependencies are listed in a comment header of the output script.

Returns

true if script needs to be compiled, false otherwise

Definition at line 166 of file Compiler.cc.

void Compiler::make ( )

private

Compiles the definition file into a task execution script.

This function compiles m_definition_file into a task execution script and writes it to the m_output_script file and then does a chmod 755 on that file. The script is assembled as follows. It tokenizes the input definition file with Tokenizer and translates each token using its corresponding translator (TranslatorCode, TranslatorRole, TranslatorTask, TranslatorVariable). After the translated tokens are written, a couple of built-in functions are generated:

Function	Description
show_variables	Displays all of the global variables and role defintion variables
with	Runs a shell command on any of the roles

After the built-in functions, argument parsing logic is added to handle the command line arguments:

Argument	Description
-T, –tasks	Displays all tasks with a short description
-e <task>, –explain <task>	Displays a detailed description of <task>
<function>	Executes <function> which is one of the task functions or or a built-in function (show_variables or with)

A comment header is written to the output script that looks something like this:

  # version: 0.9.8.1 (v0.9.8.1-35-g20a3c08)
  # dependency: /home/doug/core.tasks
  # dependency: /home/doug/test.tasks

There is one dependency: line for each file that is included with an include: directive. These header lines are used by the compilation_needed() function.

Definition at line 224 of file Compiler.cc.

string Hypertable::ClusterDefinitionFile::Compiler::output_script ( )

inline

Returns pathname of output script.

Returns

Pathname of output script

Definition at line 62 of file Compiler.h.

Member Data Documentation

string Hypertable::ClusterDefinitionFile::Compiler::m_definition_file

private

Cluster definition file.

Definition at line 138 of file Compiler.h.

string Hypertable::ClusterDefinitionFile::Compiler::m_output_script

private

Output script.

Definition at line 141 of file Compiler.h.

---

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

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