SH::DiskListXRD Class Reference

a DiskList implementation for the XRD protocol More...

#include <DiskListXRD.h>

Inheritance diagram for SH::DiskListXRD:

Collaboration diagram for SH::DiskListXRD:

Public Member Functions
void	testInvariant () const
	test the invariant of this object
	DiskListXRD (const std::string &val_server, const std::string &val_dir, bool val_laxParsing=false)
	make the listing for the given directory, but replacing the directory with prefix for the path
bool	next ()
	get the next list entry
std::string	path () const
	the path for the current entry.
std::string	fileName () const
	the filename for the current entry
DiskList *	openDir () const
	make a new list object for the sub-directory
std::unique_ptr< DiskList >	openDirUnique () const
	make a new list object for the sub-directory
std::string	dirname () const
	the base path for the directory listed

Protected Member Functions
virtual bool	getNext () override
	get the next list entry
virtual std::string	getPath () const override
	the path for the current entry.
virtual DiskList *	doOpenDir () const override
	make a new list object for the sub-directory
virtual std::string	getDirname () const override
	the base path for the directory listed

Private Types
enum	State { S_BLANK , S_VALID , S_DONE , S_BROKEN }
	the current state More...

Private Attributes
std::string	m_server
	the server from which we are reading
std::string	m_directory
	the directory we are reading
bool	m_laxParser
	whether we employ lax parsing
std::string	m_context
	the context (for error reporting)
std::string	m_list
	the result of the directory listing
std::string::size_type	m_pos = 0
	the current parse position within m_list
std::string	m_file
	the last file we read
bool	m_isDir = false
	whether this is a directory
bool	m_isRead
	whether the directory has been read
State	m_state
	the current state

Detailed Description

a DiskList implementation for the XRD protocol

Definition at line 17 of file DiskListXRD.h.

Member Enumeration Documentation

State

enum SH::DiskList::State

privateinherited

the current state

Enumerator
S_BLANK	just initialized
S_VALID	holding a valid entry
S_DONE	finished reading entries
S_BROKEN	an error occured

Definition at line 173 of file DiskList.h.

    {
      S_BLANK,  
      S_VALID,  
      S_DONE,   
      S_BROKEN  
    };

Constructor & Destructor Documentation

DiskListXRD()

SH::DiskListXRD::DiskListXRD	(	const std::string &	val_server,
		const std::string &	val_dir,
		bool	val_laxParsing = false )

make the listing for the given directory, but replacing the directory with prefix for the path

Parameters

val_dir	the directory to list
val_prefix	the prefix with which val_dir will be replaced in the reported paths
val_laxParsing	if true, graciously skip over any error messages.

Guarantee

strong

Failures

out of memory II

Rationale

this mechanism is meant to allow scanning file servers using one protocol, but then accessing them using another

Definition at line 31 of file DiskListXRD.cxx.

    : m_server (val_server), m_directory (val_directory),
      m_laxParser (val_laxParser), m_isRead (false)
  {
    RCU_NEW_INVARIANT (this);
  }

Member Function Documentation

dirname()

std::string SH::DiskList::dirname ( ) const

inherited

the base path for the directory listed

Guarantee

strong

Failures

out of memory II

Definition at line 113 of file DiskList.cxx.

  {
    RCU_READ_INVARIANT (this);
    return getDirname ();
  }

doOpenDir()

DiskList * SH::DiskListXRD::doOpenDir ( ) const

overrideprotectedvirtual

make a new list object for the sub-directory

Returns

a new list object for the sub-directory, or nullptr if it is not a directory

Precondition

(soft) next() has been called successfully

Guarantee

strong

Failures

out of memory III

Rationale

the virtual part of DiskList::openDir()

Implements SH::DiskList.

Definition at line 112 of file DiskListXRD.cxx.

  {
    RCU_READ_INVARIANT (this);
 
    if (m_file.empty() || !m_isDir)
      return nullptr;
 
    return new DiskListXRD (m_server, m_file, m_laxParser);
  }

fileName()

std::string SH::DiskList::fileName ( ) const

inherited

the filename for the current entry

Returns

the filename for the current entry

Precondition

(soft) next() has been called successfully

Guarantee

strong

Failures

out of memory III

Definition at line 80 of file DiskList.cxx.

  {
    // no invariant used
    std::string result = path();
    std::string::size_type split = result.rfind ('/');
    if (split != std::string::npos)
      result = result.substr (split + 1);
    return result;
  }

getDirname()

std::string SH::DiskListXRD::getDirname ( ) const

overrideprotectedvirtual

the base path for the directory listed

Guarantee

strong

Failures

out of memory II

Rationale

the virtual part of DiskList::dirname()

Implements SH::DiskList.

Definition at line 125 of file DiskListXRD.cxx.

  {
    RCU_READ_INVARIANT (this);
    return m_directory;
  }

getNext()

bool SH::DiskListXRD::getNext ( )

overrideprotectedvirtual

get the next list entry

Returns

whether we found another entry

Guarantee

basic

Failures

i/o errors

Rationale

the virtual part of DiskList::next()

Implements SH::DiskList.

Definition at line 42 of file DiskListXRD.cxx.

  {
    RCU_CHANGE_INVARIANT (this);
    using namespace msgScanDir;
 
    if (!m_isRead)
    {
      std::string command = "xrdfs " + RCU::Shell::quote (m_server) + " ls -l " + RCU::Shell::quote (m_directory);
      ANA_MSG_DEBUG ("trying XRD command: " << command);
      m_list = RCU::Shell::exec_read (command);
      ANA_MSG_DEBUG ("XRD command output:\n" << m_list);
      m_context = "command: " + command + "\n" + m_list;
      m_isRead = true;
      m_pos = 0;
    }
 
    // rationale: we advance a running index through m_list rather than
    //   repeatedly copying its tail, so that listing N entries costs
    //   O(N) rather than O(N^2).  a final line without a trailing
    //   newline is still processed.
    while (m_pos < m_list.size())
    {
      std::string::size_type split1 = m_list.find ('\n', m_pos);
      std::string line;
      if (split1 == std::string::npos)
      {
    line = m_list.substr (m_pos);
    m_pos = m_list.size();
      } else
      {
    line = m_list.substr (m_pos, split1 - m_pos);
    m_pos = split1 + 1;
      }
      ANA_MSG_DEBUG ("next XRD list line: " << line);
 
      std::string::size_type split2 = line.find ('/');
      if (split2 != std::string::npos &&
      (line[0] == '-' || line[0] == 'd'))
      {
    m_isDir = line[0] == 'd';
    m_file = line.substr (split2);
        ANA_MSG_DEBUG ("next XRD file found: " << m_file);
        ANA_MSG_DEBUG ("XRD file isDir: " << m_isDir);
    return true;
      }
 
      if (!line.empty())
      {
    std::string message = "failed to parse line: \"" + line + "\"\n" + m_context;
 
        ANA_MSG_WARNING (message);
    if (!m_laxParser)
          throw std::runtime_error (message);
      }
    }
    return false;
  }

getPath()

std::string SH::DiskListXRD::getPath ( ) const

overrideprotectedvirtual

the path for the current entry.

Returns

the path for the current entry

Precondition

(soft) next() has been called successfully

Guarantee

strong failures: out of memory III

Rationale

the virtual part of DiskList::path()

Implements SH::DiskList.

Definition at line 103 of file DiskListXRD.cxx.

  {
    RCU_READ_INVARIANT (this);
    return "root://" + m_server + "/" + m_file;
  }

next()

bool SH::DiskList::next ( )

inherited

get the next list entry

Returns

whether we found another entry

Guarantee

basic

Failures

i/o errors

Definition at line 46 of file DiskList.cxx.

  {
    RCU_CHANGE_INVARIANT (this);
    switch (m_state)
    {
    case S_BLANK:
    case S_VALID:
      m_state = S_BROKEN;
      if (getNext())
    m_state = S_VALID;
      else
    m_state = S_DONE;
      return m_state == S_VALID;
    case S_DONE:
      throw std::runtime_error ("DiskList::next: already finished processing list");
    case S_BROKEN:
      throw std::runtime_error ("DiskList::next: list is in error state");
    };
    return false; // compiler dummy
  }

openDir()

DiskList * SH::DiskList::openDir ( ) const

inherited

make a new list object for the sub-directory

Returns

a new list object for the sub-directory, or nullptr if it is not a directory

Precondition

(soft) next() has been called successfully

Guarantee

strong

Failures

out of memory III

Definition at line 93 of file DiskList.cxx.

  {
    RCU_READ_INVARIANT (this);
    RCU_REQUIRE2_SOFT (m_state == S_VALID, "getNext() has not been called successfully");
    return doOpenDir();
  }

openDirUnique()

std::unique_ptr< DiskList > SH::DiskList::openDirUnique ( ) const

inherited

make a new list object for the sub-directory

Returns

a new list object for the sub-directory, or nullptr if it is not a directory

Precondition

(soft) next() has been called successfully

Guarantee

strong

Failures

out of memory III

Definition at line 103 of file DiskList.cxx.

  {
    RCU_READ_INVARIANT (this);
    RCU_REQUIRE2_SOFT (m_state == S_VALID, "getNext() has not been called successfully");
    return std::unique_ptr<DiskList> (doOpenDir());
  }

path()

std::string SH::DiskList::path ( ) const

inherited

the path for the current entry.

Returns

the path for the current entry

Precondition

(soft) next() has been called successfully

Guarantee

strong failures: out of memory III

Definition at line 70 of file DiskList.cxx.

  {
    RCU_READ_INVARIANT (this);
    RCU_REQUIRE2_SOFT (m_state == S_VALID, "getNext() has not been called successfully");
    return getPath();
  }

testInvariant()

void SH::DiskListXRD::testInvariant

(

)

const

test the invariant of this object

Guarantee

no-fail

Definition at line 24 of file DiskListXRD.cxx.

  {
  }

Member Data Documentation

m_context

std::string SH::DiskListXRD::m_context

private

the context (for error reporting)

Definition at line 96 of file DiskListXRD.h.

m_directory

std::string SH::DiskListXRD::m_directory

private

the directory we are reading

Definition at line 88 of file DiskListXRD.h.

m_file

std::string SH::DiskListXRD::m_file

private

the last file we read

Definition at line 108 of file DiskListXRD.h.

m_isDir

bool SH::DiskListXRD::m_isDir = false

private

whether this is a directory

Definition at line 112 of file DiskListXRD.h.

m_isRead

bool SH::DiskListXRD::m_isRead

private

whether the directory has been read

Definition at line 116 of file DiskListXRD.h.

m_laxParser

bool SH::DiskListXRD::m_laxParser

private

whether we employ lax parsing

Definition at line 92 of file DiskListXRD.h.

m_list

std::string SH::DiskListXRD::m_list

private

the result of the directory listing

Definition at line 100 of file DiskListXRD.h.

m_pos

std::string::size_type SH::DiskListXRD::m_pos = 0

private

the current parse position within m_list

Definition at line 104 of file DiskListXRD.h.

m_server

std::string SH::DiskListXRD::m_server

private

the server from which we are reading

Definition at line 84 of file DiskListXRD.h.

m_state

State SH::DiskList::m_state

privateinherited

the current state

Definition at line 181 of file DiskList.h.

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

• DiskListXRD.h
• DiskListXRD.cxx