Class: Hocon::Impl::ConfigDelayedMerge

Inherits:
Object
  • Object
show all
Includes:
AbstractConfigValue, ReplaceableMergeStack, Unmergeable
Defined in:
lib/hocon/impl/config_delayed_merge.rb

Overview

The issue here is that we want to first merge our stack of config files, and then we want to evaluate substitutions. But if two substitutions both expand to an object, we might need to merge those two objects. Thus, we can’t ever “override” a substitution when we do a merge; instead we have to save the stack of values that should be merged, and resolve the merge when we evaluate substitutions.

Constant Summary collapse

ConfigImpl = 
Hocon::Impl::ConfigImpl
ResolveResult = 
Hocon::Impl::ResolveResult

Constants included from AbstractConfigValue

AbstractConfigValue::ConfigBugOrBrokenError, AbstractConfigValue::ConfigImplUtil, AbstractConfigValue::ResolveStatus

Instance Attribute Summary collapse

Attributes included from AbstractConfigValue

#origin

Class Method Summary collapse

Instance Method Summary collapse

Methods included from AbstractConfigValue

#at_key, #at_key_with_origin, #at_path, #at_path_with_origin, #construct_delayed_merge, #delay_merge, has_descendant_in_list?, indent, #inspect, #merged_stack_with_non_object, #merged_stack_with_object, #merged_stack_with_the_unmergeable, #render, #render_value_to_sb, replace_child_in_list, #require_not_ignoring_fallbacks, #to_fallback_value, #to_s, #transform_to_string, #with_fallback, #with_fallbacks_ignored, #with_origin

Methods included from ConfigValue

#at_key, #at_path, #origin, #render, #with_fallback, #with_origin

Methods included from ConfigMergeable

#with_fallback

Constructor Details

#initialize(origin, stack) ⇒ ConfigDelayedMerge

Returns a new instance of ConfigDelayedMerge.



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 24

def initialize(origin, stack)
  super(origin)
  @stack = stack

  if stack.empty?
    raise Hocon::ConfigError::ConfigBugOrBrokenError.new("creating empty delayed merge value", nil)
  end

  stack.each do |v|
    if v.is_a?(Hocon::Impl::ConfigDelayedMerge) || v.is_a?(Hocon::Impl::ConfigDelayedMergeObject)
      error_message = "placed nested DelayedMerge in a ConfigDelayedMerge, should have consolidated stack"
      raise Hocon::ConfigError::ConfigBugOrBrokenError.new(error_message, nil)
    end
  end
end

Instance Attribute Details

#stack ⇒ Object (readonly)

Returns the value of attribute stack.



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 40

def stack
  @stack
end

Class Method Details

.make_replacement(context, stack, skipping) ⇒ Object

static method also used by ConfigDelayedMergeObject; end may be null



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 159

def self.make_replacement(context, stack, skipping)
  sub_stack = stack.slice(skipping..stack.size)

  if sub_stack.empty?
    if ConfigImpl.trace_substitution_enabled
      ConfigImpl.trace("Nothing else in the merge stack, replacing with null", context.depth)
      return nil
    end
  else
    # generate a new merge stack from only the remaining items
    merged = nil
    sub_stack.each do |v|
      if merged.nil?
        merged = v
      else
        merged = merged.with_fallback(v)
      end
    end
    merged
  end
end

.render_value_to_sb_from_stack(stack, sb, indent, at_root, at_key, options) ⇒ Object

static method also used by ConfigDelayedMergeObject.



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 256

def self.render_value_to_sb_from_stack(stack, sb, indent, at_root, at_key, options)
  comment_merge = options.comments

  if comment_merge
    sb << "# unresolved merge of #{stack.size} values follows (\n"
    if at_key.nil?
      self.indent(sb, indent, options)
      sb << "# this unresolved merge will not be parseable because it's at the root of the object\n"
      self.indent(sb, indent, options)
      sb << "# the HOCON format has no way to list multiple root objects in a single file\n"
    end
  end

  reversed = stack.reverse

  i = 0

  reversed.each do |v|
    if comment_merge
      self.indent(sb, indent, options)
      if !at_key.nil?
        rendered_key = Hocon::Impl::ConfigImplUtil.render_json_string(at_key)
        sb << "#     unmerged value #{i} for key #{rendered_key}"
      else
        sb << "#     unmerged value #{i} from "
      end
      i += 1

      sb << v.origin.description
      sb << "\n"

      v.origin.comments.each do |comment|
        self.indent(sb, indent, options)
        sb << "# "
        sb << comment
        sb << "\n"
      end
    end
    Hocon::Impl::AbstractConfigValue.indent(sb, indent, options)

    if !at_key.nil?
      sb << Hocon::Impl::ConfigImplUtil.render_json_string(at_key)
      if options.formatted
        sb << " : "
      else
        sb << ":"
      end
    end

    v.render_value_to_sb(sb, indent, at_root, options)
    sb << ","

    if options.formatted
      sb.append "\n"
    end
  end

  # chop comma or newline
  # couldn't figure out a better way to chop characters off of the end of
  # the StringIO.  This relies on making sure that, prior to returning the
  # final string, we take a substring that ends at sb.pos.
  sb.pos = sb.pos - 1
  if options.formatted
    sb.pos = sb.pos - 1
    sb << "\n"
  end

  if comment_merge
    self.indent(sb, indent, options)
    sb << "# ) end of unresolved merge\n"
  end
end

.resolve_substitutions(replaceable, stack, context, source) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 57

def self.resolve_substitutions(replaceable, stack, context, source)
  if ConfigImpl.trace_substitution_enabled
    ConfigImpl.trace("delayed merge stack has #{stack.size} items:", context.depth)
    count = 0
    stack.each do |v|
      ConfigImpl.trace("#{count}: #{v}", context.depth)
      count += 1
    end
  end

  # to resolve substitutions, we need to recursively resolve
  # the stack of stuff to merge, and merge the stack so
  # we won't be a delayed merge anymore. If restrictToChildOrNull
  # is non-null, or resolve options allow partial resolves,
  # we may remain a delayed merge though.

  new_context = context
  count = 0
  merged = nil
  stack.each do |stack_end|
    # the end value may or may not be resolved already

    if stack_end.is_a?(Hocon::Impl::ReplaceableMergeStack)
      raise ConfigBugOrBrokenError, "A delayed merge should not contain another one: #{replaceable}"
    elsif stack_end.is_a?(Hocon::Impl::Unmergeable)
      # the remainder could be any kind of value, including another
      # ConfigDelayedMerge
      remainder = replaceable.make_replacement(context, count + 1)

      if ConfigImpl.trace_substitution_enabled
        ConfigImpl.trace("remainder portion: #{remainder}", new_context.depth)
      end

      # If, while resolving 'end' we come back to the same
      # merge stack, we only want to look _below_ 'end'
      # in the stack. So we arrange to replace the
      # ConfigDelayedMerge with a value that is only
      # the remainder of the stack below this one.

      if ConfigImpl.trace_substitution_enabled
        ConfigImpl.trace("building sourceForEnd", new_context.depth)
      end

      # we resetParents() here because we'll be resolving "end"
      # against a root which does NOT contain "end"
      source_for_end = source.replace_within_current_parent(replaceable, remainder)

      if ConfigImpl.trace_substitution_enabled
        ConfigImpl.trace("  sourceForEnd before reset parents but after replace: #{source_for_end}", new_context.depth)
      end

      source_for_end = source_for_end.reset_parents
    else
      if ConfigImpl.trace_substitution_enabled
        ConfigImpl.trace("will resolve end against the original source with parent pushed",
                         new_context.depth)
      end

      source_for_end = source.push_parent(replaceable)
    end

    if ConfigImpl.trace_substitution_enabled
      ConfigImpl.trace("sourceForEnd      =#{source_for_end}", new_context.depth)
    end

    if ConfigImpl.trace_substitution_enabled
      ConfigImpl.trace("Resolving highest-priority item in delayed merge #{stack_end}" +
                        " against #{source_for_end} endWasRemoved=#{(source != source_for_end)}")
    end

    result = new_context.resolve(stack_end, source_for_end)
    resolved_end = result.value
    new_context = result.context

    if ! resolved_end.nil?
      if merged.nil?
        merged = resolved_end
      else
        if ConfigImpl.trace_substitution_enabled
          ConfigImpl.trace("merging #{merged} with fallback #{resolved_end}",
                           new_context.depth + 1)
        end
        merged = merged.with_fallback(resolved_end)
      end
    end

    count += 1

    if ConfigImpl.trace_substitution_enabled
      ConfigImpl.trace("stack merged, yielding: #{merged}",
                       new_context.depth)
    end
  end

  ResolveResult.make(new_context, merged)
end

.stack_ignores_fallbacks?(stack) ⇒ Boolean

static utility shared with ConfigDelayedMergeObject

Returns:

  • (Boolean) 


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# File 'lib/hocon/impl/config_delayed_merge.rb', line 204

def self.stack_ignores_fallbacks?(stack)
  last = stack[-1]
  last.ignores_fallbacks?
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 237

def ==(other)
  # note that "origin" is deliberately NOT part of equality
  if other.is_a? Hocon::Impl::ConfigDelayedMerge
    can_equal(other) && (@stack == other.stack || @stack.equal?(other.stack))
  else
    false
  end
end

#can_equal(other) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 233

def can_equal(other)
  other.is_a? Hocon::Impl::ConfigDelayedMerge
end

#has_descendant?(descendant) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/hocon/impl/config_delayed_merge.rb', line 194

def has_descendant?(descendant)
  Hocon::Impl::AbstractConfigValue.has_descendant_in_list?(stack, descendant)
end

#hash ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 246

def hash
  # note that "origin" is deliberately NOT part of equality
  @stack.hash
end

#ignores_fallbacks? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/hocon/impl/config_delayed_merge.rb', line 209

def ignores_fallbacks?
  self.class.stack_ignores_fallbacks?(stack)
end

#make_replacement(context, skipping) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 154

def make_replacement(context, skipping)
  self.class.make_replacement(context, @stack, skipping)
end

#merged_with_non_object(fallback) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 225

def merged_with_non_object(fallback)
  merged_stack_with_non_object(stack, fallback)
end

#merged_with_object(fallback) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 221

def merged_with_object(fallback)
  merged_stack_with_object(stack, fallback)
end

#merged_with_the_unmergeable(fallback) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 217

def merged_with_the_unmergeable(fallback)
  merged_stack_with_the_unmergeable(stack, fallback)
end

#new_copy(new_origin) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 213

def new_copy(new_origin)
  self.class.new(new_origin, stack)
end

#relativized(prefix) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 198

def relativized(prefix)
  new_stack = stack.map { |o| o.relativized(prefix) }
  self.class.new(origin, new_stack)
end

#render_to_sb(sb, indent, at_root, at_key, options) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 251

def render_to_sb(sb, indent, at_root, at_key, options)
  self.class.render_value_to_sb_from_stack(stack, sb, indent, at_root, at_key, options)
end

#replace_child(child, replacement) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 185

def replace_child(child, replacement)
  new_stack = replace_child_in_list(stack, child, replacement)
  if new_stack.nil?
    nil
  else
    self.class.new(origin, new_stack)
  end
end

#resolve_status ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 181

def resolve_status
  Hocon::Impl::ResolveStatus::UNRESOLVED
end

#resolve_substitutions(context, source) ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 53

def resolve_substitutions(context, source)
  self.class.resolve_substitutions(self, stack, context, source)
end

#unmerged_values ⇒ Object 



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 229

def unmerged_values
  stack
end

#unwrapped ⇒ Object

Raises:



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 48

def unwrapped
  error_message = "called unwrapped() on value with unresolved substitutions, need to Config#resolve() first, see API docs"
  raise Hocon::ConfigError::ConfigNotResolvedError.new(error_message, nil)
end

#value_type ⇒ Object

Raises:



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# File 'lib/hocon/impl/config_delayed_merge.rb', line 43

def value_type
  error_message = "called value_type() on value with unresolved substitutions, need to Config#resolve() first, see API docs"
  raise Hocon::ConfigError::ConfigNotResolvedError.new(error_message, nil)
end