a DiskList implementation for the SRM protocol More...

#include <DiskListSRM.h>

Inheritance diagram for SH::DiskListSRM:

Collaboration diagram for SH::DiskListSRM:

Public Member Functions
void	testInvariant () const
	test the invariant of this object
	DiskListSRM (const std::string &val_dir)
	make the listing for the given directory
	DiskListSRM (const std::string &val_dir, const std::string &val_prefix)
	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_dir
	the directory we are reading
std::string	m_prefix
	the directory from with to read actual files
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 = false
	whether the directory has been read
State	m_state
	the current state

Detailed Description

a DiskList implementation for the SRM protocol

Definition at line 17 of file DiskListSRM.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

◆ DiskListSRM() [1/2]

SH::DiskListSRM::DiskListSRM ( const std::string & val_dir )

make the listing for the given directory

Parameters

val_dir the directory to list

Guarantee: strong

Failures: out of memory II

Definition at line 29 of file DiskListSRM.cxx.

    : m_dir (val_dir), m_prefix (val_dir)
  {
    RCU_NEW_INVARIANT (this);
  }

◆ DiskListSRM() [2/2]

SH::DiskListSRM::DiskListSRM	(	const std::string &	val_dir,
		const std::string &	val_prefix )

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

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 38 of file DiskListSRM.cxx.

    : m_dir (val_dir), m_prefix (val_prefix)
  {
    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::DiskListSRM::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 110 of file DiskListSRM.cxx.

  {
    RCU_READ_INVARIANT (this);
 
    if (m_file.empty() || !m_isDir)
      return nullptr;
 
    return new DiskListSRM (m_dir + "/" + m_file, m_prefix + "/" + m_file);
  }

◆ 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::DiskListSRM::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 123 of file DiskListSRM.cxx.

  {
    RCU_READ_INVARIANT (this);
    return m_dir;
  }

◆ getNext()

bool SH::DiskListSRM::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 47 of file DiskListSRM.cxx.

  {
    RCU_CHANGE_INVARIANT (this);
 
    if (!m_isRead)
    {
      m_list = RCU::Shell::exec_read ("srmls " + RCU::Shell::quote (m_dir));
      m_isRead = true;
      m_pos = 0;
      // rationale: skip the header line of the srmls output
      std::string::size_type split1 = m_list.find ('\n');
      if (split1 == std::string::npos)
    return false;
      m_pos = split1 + 1;
    }
 
    // 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).
    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;
      }
      if (line.size() > 2)
      {
    std::string::size_type split2 = line.rfind ('/', line.size()-2);
    if (split2 != std::string::npos)
    {
      m_file = line.substr (split2 + 1);
      if (m_file[m_file.size()-1] == '/')
      {
        m_isDir = true;
            m_file.resize (m_file.size()-1);
      } else
        m_isDir = false;
      return true;
    }
      }
    }
    return false;
  }

◆ getPath()

std::string SH::DiskListSRM::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 101 of file DiskListSRM.cxx.

  {
    RCU_READ_INVARIANT (this);
    return m_prefix + "/" + 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::DiskListSRM::testInvariant ( ) const

test the invariant of this object

Guarantee: no-fail

Definition at line 22 of file DiskListSRM.cxx.

24 {

25 }

Member Data Documentation

◆ m_dir

std::string SH::DiskListSRM::m_dir

private

the directory we are reading

Definition at line 92 of file DiskListSRM.h.

◆ m_file

std::string SH::DiskListSRM::m_file

private

the last file we read

Definition at line 108 of file DiskListSRM.h.

◆ m_isDir

bool SH::DiskListSRM::m_isDir = false

private

whether this is a directory

Definition at line 112 of file DiskListSRM.h.

◆ m_isRead

bool SH::DiskListSRM::m_isRead = false

private

whether the directory has been read

Definition at line 116 of file DiskListSRM.h.

◆ m_list

std::string SH::DiskListSRM::m_list

private

the result of the directory listing

Definition at line 100 of file DiskListSRM.h.

◆ m_pos

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

private

the current parse position within m_list

Definition at line 104 of file DiskListSRM.h.

◆ m_prefix

std::string SH::DiskListSRM::m_prefix

private

the directory from with to read actual files

Definition at line 96 of file DiskListSRM.h.

◆ m_state

State SH::DiskList::m_state

privateinherited

the current state

Definition at line 181 of file DiskList.h.

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

Public Member Functions

Protected Member Functions

Private Types

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ State

Constructor & Destructor Documentation

◆ DiskListSRM() [1/2]

◆ DiskListSRM() [2/2]

Member Function Documentation

◆ dirname()

◆ doOpenDir()

◆ fileName()

◆ getDirname()

◆ getNext()

◆ getPath()

◆ next()

◆ openDir()

◆ openDirUnique()

◆ path()

◆ testInvariant()

Member Data Documentation

◆ m_dir

◆ m_file

◆ m_isDir

◆ m_isRead

◆ m_list

◆ m_pos

◆ m_prefix

◆ m_state