Class: Chef::ChefFS::FileSystem::BaseFSObject

Inherits:
Object
  • Object
show all
Defined in:
lib/chef/chef_fs/file_system/base_fs_object.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, parent) ⇒ BaseFSObject

Returns a new instance of BaseFSObject.



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 26

def initialize(name, parent)
  @parent = parent
  @name = name
  if parent
    @path = Chef::ChefFS::PathUtils.join(parent.path, name)
  else
    if name != ""
      raise ArgumentError, "Name of root object must be empty string: was '#{name}' instead"
    end
    @path = "/"
  end
end

Instance Attribute Details

#name ⇒ Object (readonly) Also known as: display_name, bare_name

Returns the value of attribute name.



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 39

def name
  @name
end

#parent ⇒ Object (readonly)

Returns the value of attribute parent.



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 40

def parent
  @parent
end

#path ⇒ Object (readonly) Also known as: display_path

Returns the value of attribute path.



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 41

def path
  @path
end

Instance Method Details

#can_have_child?(name, is_dir) ⇒ Boolean

Override can_have_child? to report whether a given file could be added to this directory. (Some directories can’t have subdirs, some can only have .json files, etc.)

Returns:

  • (Boolean) 


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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 87

def can_have_child?(name, is_dir)
  false
end

#chef_object ⇒ Object

Expand this entry into a chef object (Chef::Role, ::Node, etc.)

Raises:



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 115

def chef_object
  raise NotFoundError.new(self) if !exists?
  nil
end

#child(name) ⇒ Object

Get a child of this entry with the given name. This MUST always return a child, even if it is NonexistentFSObject. Overriders should take caution not to do expensive network requests to get the list of children to fulfill this request, unless absolutely necessary here; it is intended as a quick way to traverse a hierarchy.

For example, knife show /data_bags/x/y.json will call root.child(‘data_bags’).child(‘x’).child(‘y.json’), which can then directly perform a network request to retrieve the y.json data bag. No network request was necessary to retrieve



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 101

def child(name)
  if can_have_child?(name, true) || can_have_child?(name, false)
    result = make_child_entry(name)
  end
  result || NonexistentFSObject.new(name, self)
end

#children ⇒ Object

Override children to report your actual list of children as an array.

Raises:



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 109

def children
  raise NotFoundError.new(self) if !exists?
  []
end

#compare_to(other) ⇒ Object

Override this if you have a special comparison algorithm that can tell you whether this entry is the same as another–either a quicker or a more reliable one. Callers will use this to decide whether to upload, download or diff an object.

You should not override this if you’re going to do the standard self.read == other.read. If you return nil, the caller will call other.compare_to(you) instead. Give them a chance :)

Parameters

  • other - the entry to compare to

Returns

  • [ are_same, value, other_value ] are_same may be true, false or nil (which means “don’t know”). value and other_value must either be the text of self or other, :none (if the entry does not exist or has no value) or nil if the value was not retrieved.

  • nil if a definitive answer cannot be had and nothing was retrieved.

Example

are_same, value, other_value = entry.compare_to(other)
if are_same.nil?
  are_same, other_value, value = other.compare_to(entry)
end
if are_same.nil?
  value = entry.read if value.nil?
  other_value = entry.read if other_value.nil?
  are_same = (value == other_value)
end



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 80

def compare_to(other)
  nil
end

#create_child(name, file_contents) ⇒ Object

Create a child of this entry with the given name and contents. If contents is nil, create a directory.

NOTE: create_child_from is an optional method that can also be added to your entry class, and will be called without actually reading the file_contents. This is used for knife upload /cookbooks/cookbookname.

Raises:



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 126

def create_child(name, file_contents)
  raise NotFoundError.new(self) if !exists?
  raise OperationNotAllowedError.new(:create_child, self)
end

#delete(recurse) ⇒ Object

Delete this item, possibly recursively. Entries MUST NOT delete a directory unless recurse is true.

Raises:



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 133

def delete(recurse)
  raise NotFoundError.new(self) if !exists?
  raise OperationNotAllowedError.new(:delete, self)
end

#dir? ⇒ Boolean

Ask whether this entry is a directory. If not, it is a file.

Returns:

  • (Boolean) 


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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 139

def dir?
  false
end

#exists? ⇒ Boolean

Ask whether this entry exists.

Returns:

  • (Boolean) 


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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 144

def exists?
  true
end

#path_for_printing ⇒ Object

Printable path, generally used to distinguish paths in one root from paths in another.



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 150

def path_for_printing
  if parent
    parent_path = parent.path_for_printing
    if parent_path == "."
      name
    else
      Chef::ChefFS::PathUtils.join(parent.path_for_printing, name)
    end
  else
    name
  end
end

#read ⇒ Object

Read the contents of this file entry.

Raises:



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 168

def read
  raise NotFoundError.new(self) if !exists?
  raise OperationNotAllowedError.new(:read, self)
end

#root ⇒ Object 



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 163

def root
  parent ? parent.root : self
end

#write(file_contents) ⇒ Object

Write the contents of this file entry.

Raises:



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# File 'lib/chef/chef_fs/file_system/base_fs_object.rb', line 174

def write(file_contents)
  raise NotFoundError.new(self) if !exists?
  raise OperationNotAllowedError.new(:write, self)
end