Fiddle::Importer

Included modules:Fiddle, Fiddle::CParser

一个DSL提供了动态加载库和构建模块的方法，包括调用已加载的C库中的extern函数。

例

require 'fiddle'
require 'fiddle/import'

module LibSum
  extend Fiddle::Importer
  dlload './libsum.so'
  extern 'double sum(double*, int)'
  extern 'double split(double)'
end

属性

type_aliasR

公共实例方法

Show source

返回映射到名称的函数，该函数由#extern或#bind创建

# File ext/fiddle/lib/fiddle/import.rb, line 232
def [](name)
  @func_map[name]
end

bind(signature, *opts, &blk) Show source

使用给定的opts作为给定块的绑定参数，从给定的C signature

创建一个全局方法。

# File ext/fiddle/lib/fiddle/import.rb, line 188
    def bind(signature, *opts, &blk)
      name, ctype, argtype = parse_signature(signature, type_alias)
      h = parse_bind_options(opts)
      case h[:callback_type]
      when :bind, nil
        f = bind_function(name, ctype, argtype, h[:call_type], &blk)
      else
        raise(RuntimeError, "unknown callback type: #{h[:callback_type]}")
      end
      @func_map[name] = f
      #define_method(name){|*args,&block| f.call(*args,&block)}
      begin
        /^(.+?):(\d+)/ =~ caller.first
        file, line = $1, $2.to_i
      rescue
        file, line = __FILE__, __LINE__+3
      end
      module_eval("        def #{name}(*args,&block)
          @func_map['#{name}'].call(*args,&block)
        end
", file, line)
      module_function(name)
      f
    end

bind_function(name, ctype, argtype, call_type = nil, &block) Show source

为name函数返回一个新的封闭包装。

• ctype 是函数的返回类型

• argtype 是一个传递给回调函数的参数数组

• call_type 是关闭的abi

• block 传递给回调

See Fiddle::Closure

# File ext/fiddle/lib/fiddle/import.rb, line 308
def bind_function(name, ctype, argtype, call_type = nil, &block)
  abi = CALL_TYPE_TO_ABI[call_type]
  closure = Class.new(Fiddle::Closure) {
    define_method(:call, block)
  }.new(ctype, argtype, abi)

  Function.new(closure, argtype, ctype, abi, name: name)
end

create_value(ty, val=nil) Show source

创建一个类来包装具有值ty的C结构

另见#struct

# File ext/fiddle/lib/fiddle/import.rb, line 239
def create_value(ty, val=nil)
  s = struct([ty + " value"])
  ptr = s.malloc()
  if( val )
    ptr.value = val
  end
  return ptr
end

别名：值

dlload(*libs) Show source

为给定的数组创建一个处理程序数组libs，可以是Fiddle :: Handle，Fiddle :: Importer的一个实例，或者将使用Fiddle＃dlopen创建Fiddle :: Handle的新实例

如果库无法加载，则引发DLError。

请参阅Fiddle＃dlopen

# File ext/fiddle/lib/fiddle/import.rb, line 75
def dlload(*libs)
  handles = libs.collect{|lib|
    case lib
    when nil
      nil
    when Handle
      lib
    when Importer
      lib.handlers
    else
      begin
        Fiddle.dlopen(lib)
      rescue DLError
        raise(DLError, "can't load #{lib}")
      end
    end
  }.flatten()
  @handler = CompositeHandler.new(handles)
  @func_map = {}
  @type_alias = {}
end

extern(signature, *opts) Show source

根据给定的C signature创建一个全局方法。

# File ext/fiddle/lib/fiddle/import.rb, line 164
    def extern(signature, *opts)
      symname, ctype, argtype = parse_signature(signature, type_alias)
      opt = parse_bind_options(opts)
      f = import_function(symname, ctype, argtype, opt[:call_type])
      name = symname.gsub(/@.+/,'')
      @func_map[name] = f
      # define_method(name){|*args,&block| f.call(*args,&block)}
      begin
        /^(.+?):(\d+)/ =~ caller.first
        file, line = $1, $2.to_i
      rescue
        file, line = __FILE__, __LINE__+3
      end
      module_eval("        def #{name}(*args, &block)
          @func_map['#{name}'].call(*args,&block)
        end
", file, line)
      module_function(name)
      f
    end

handler() Show source

The Fiddle::CompositeHandler instance

如果没有处理程序处于打开状态，则会引发错误。

# File ext/fiddle/lib/fiddle/import.rb, line 261
def handler
  (@handler ||= nil) or raise "call dlload before importing symbols and functions"
end

import_function(name, ctype, argtype, call_type = nil) Show source

在给定name函数的内存地址返回一个新的Fiddle :: Function实例。

如果name不存在，则引发DLError 。

• argtype是传递给name函数的一个参数数组。

• ctype 是函数的返回类型

• call_type 是函数的ABI

另请参见Fiddle:Function.new

请参阅Fiddle :: CompositeHandler＃sym 和 Fiddle :: Handler.sym

# File ext/fiddle/lib/fiddle/import.rb, line 291
def import_function(name, ctype, argtype, call_type = nil)
  addr = handler.sym(name)
  if( !addr )
    raise(DLError, "cannot find the function: #{name}()")
  end
  Function.new(addr, argtype, ctype, CALL_TYPE_TO_ABI[call_type],
               name: name)
end

import_symbol(name) Show source

在给定名称符号的内存地址返回一个新的Fiddle :: Pointer实例。

如果name不存在，则引发DLError 。

请参阅Fiddle :: CompositeHandler＃sym 和 Fiddle :: Handle.sym

# File ext/fiddle/lib/fiddle/import.rb, line 271
def import_symbol(name)
  addr = handler.sym(name)
  if( !addr )
    raise(DLError, "cannot find the symbol: #{name}")
  end
  Pointer.new(addr)
end

import_value(ty, addr) Show source

返回地址为addr的值为ty的C结构的新实例。

# File ext/fiddle/lib/fiddle/import.rb, line 251
def import_value(ty, addr)
  s = struct([ty + " value"])
  ptr = s.new(addr)
  return ptr
end

sizeof(ty) Show source

返回sizeof ty，使用Fiddle :: CParser＃parse_ctype来确定C类型和适当的Fiddle常量。

# File ext/fiddle/lib/fiddle/import.rb, line 104
def sizeof(ty)
  case ty
  when String
    ty = parse_ctype(ty, type_alias).abs()
    case ty
    when TYPE_CHAR
      return SIZEOF_CHAR
    when TYPE_SHORT
      return SIZEOF_SHORT
    when TYPE_INT
      return SIZEOF_INT
    when TYPE_LONG
      return SIZEOF_LONG
    when TYPE_LONG_LONG
      return SIZEOF_LONG_LONG
    when TYPE_FLOAT
      return SIZEOF_FLOAT
    when TYPE_DOUBLE
      return SIZEOF_DOUBLE
    when TYPE_VOIDP
      return SIZEOF_VOIDP
    else
      raise(DLError, "unknown type: #{ty}")
    end
  when Class
    if( ty.instance_methods().include?(:to_ptr) )
      return ty.size()
    end
  end
  return Pointer[ty].size()
end

struct(signature) Show source

创建一个类来包装由signature描述的C结构。

MyStruct = struct ['int i', 'char c']

# File ext/fiddle/lib/fiddle/import.rb, line 217
def struct(signature)
  tys, mems = parse_struct_signature(signature, type_alias)
  Fiddle::CStructBuilder.create(CStruct, tys, mems)
end

typealias(alias_type, orig_type) Show source

将alias_type的类型别名设置为orig_type

# File ext/fiddle/lib/fiddle/import.rb, line 98
def typealias(alias_type, orig_type)
  @type_alias[alias_type] = orig_type
end

union(signature) Show source

创建一个类来包装由signature描述的C联合。

MyUnion = union ['int i', 'char c']

# File ext/fiddle/lib/fiddle/import.rb, line 225
def union(signature)
  tys, mems = parse_struct_signature(signature, type_alias)
  Fiddle::CStructBuilder.create(CUnion, tys, mems)
end

value(ty, val=nil)

别名为：create_value

私有实例方法

parse_bind_options(opts) Show source

# File ext/fiddle/lib/fiddle/import.rb, line 136
def parse_bind_options(opts)
  h = {}
  while( opt = opts.shift() )
    case opt
    when :stdcall, :cdecl
      h[:call_type] = opt
    when :carried, :temp, :temporal, :bind
      h[:callback_type] = opt
      h[:carrier] = opts.shift()
    else
      h[opt] = true
    end
  end
  h
end