Class: FFI::AbstractMemory

Inherits:
Object
  • Object
show all
Defined in:
ext/ffi_c/AbstractMemory.c,
lib/ffi/abstract_memory.rb,
ext/ffi_c/AbstractMemory.c

Overview

AbstractMemory is the base class for many memory management classes such as Buffer.

This class has a lot of methods to work with integers :

  • put_intsize(offset, value)

  • get_intsize(offset)

  • put_uintsize(offset, value)

  • get_uintsize(offset)

  • writeuintsize(value)

  • read_intsize

  • write_uintsize(value)

  • read_uintsize

  • put_array_of_intsize(offset, ary)

  • get_array_of_intsize(offset, length)

  • put_array_of_uintsize(offset, ary)

  • get_array_of_uintsize(offset, length)

  • write_array_of_intsize(ary)

  • read_array_of_intsize(length)

  • write_array_of_uintsize(ary)

  • read_array_of_uintsize(length)

where size is 8, 16, 32 or 64. Same methods exist for long type.

Aliases exist : char for int8, short for int16, int for int32 and long_long for int64.

Others methods are listed below.

Direct Known Subclasses

Buffer, Pointer

Constant Summary collapse

LONG_MAX = 
FFI::Pointer.new(1).size

Instance Method Summary collapse

Instance Method Details

#[](idx) ⇒ Object

Memory read accessor.

Parameters:

  • idx (Numeric) —

    index to access in memory

Returns:


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# File 'ext/ffi_c/AbstractMemory.c', line 648

static VALUE
memory_aref(VALUE self, VALUE idx)
{
    AbstractMemory* ptr;
    VALUE rbOffset = Qnil;

    Data_Get_Struct(self, AbstractMemory, ptr);

    rbOffset = ULONG2NUM(NUM2ULONG(idx) * ptr->typeSize);

    return rb_funcall2(self, id_plus, 1, &rbOffset);
}

#__copy_from__(rbsrc, rblen) ⇒ Object 


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# File 'ext/ffi_c/AbstractMemory.c', line 667

static VALUE
memory_copy_from(VALUE self, VALUE rbsrc, VALUE rblen)
{
    AbstractMemory* dst;

    Data_Get_Struct(self, AbstractMemory, dst);

    memcpy(dst->address, rbffi_AbstractMemory_Cast(rbsrc, rbffi_AbstractMemoryClass)->address, NUM2INT(rblen));

    return self;
}

#clear ⇒ self

Set the memory to all-zero.

Returns:

  • (self) 

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# File 'ext/ffi_c/AbstractMemory.c', line 306

static VALUE
memory_clear(VALUE self)
{
    AbstractMemory* ptr = MEMORY(self);
    memset(ptr->address, 0, ptr->size);
    return self;
}

#get(type, offset) ⇒ Object

Return data of given type contained in memory.

Parameters:

  • type_name (Symbol, Type) —

    type of data to get

  • offset (Numeric) —

    point in buffer to start from

Returns:

  • (Object)

Raises:

  • (ArgumentError) —

    if type is not supported


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# File 'ext/ffi_c/AbstractMemory.c', line 337

static VALUE
memory_get(VALUE self, VALUE type_name, VALUE offset)
{
    AbstractMemory* ptr;
    VALUE nType;
    Type *type;

    nType = rbffi_Type_Lookup(type_name);
    if(NIL_P(nType)) goto undefined_type;

    Data_Get_Struct(self, AbstractMemory, ptr);
    Data_Get_Struct(nType, Type, type);

    MemoryOp *op = get_memory_op(type);
    if(op == NULL) goto undefined_type;

    return op->get(ptr, NUM2LONG(offset));

undefined_type: {
    VALUE msg = rb_sprintf("undefined type '%" PRIsVALUE "'", type_name);
    rb_exc_raise(rb_exc_new3(rb_eArgError, msg));
    return Qnil;
  }
}

#get_array_of_float32(offset, length) ⇒ Array<Float> Also known as: get_array_of_float

Get 32-bit floats in memory from offset offset (alias: #get_array_of_float).

Parameters:

  • offset (Numeric)
  • length (Numeric) —

    number of Float to get

Returns:

  • (Array<Float>)

#get_array_of_float64(offset, length) ⇒ Array<Float> Also known as: get_array_of_double

Get 64-bit floats (doubles) in memory from offset offset (alias: #get_array_of_double).

Parameters:

  • offset (Numeric)
  • length (Numeric) —

    number of Float to get

Returns:

  • (Array<Float>)

#get_array_of_pointer(offset, length) ⇒ Array<Pointer>

Get an array of Pointer of length length from offset.

Parameters:

  • offset (Numeric)
  • length (Numeric)

Returns:

#get_array_of_string(offset, count = nil) ⇒ Array<String>

Return an array of strings contained in memory.

Parameters:

  • offset (Numeric) —

    point in memory to start from

  • count (Numeric) —

    number of strings to get. If nil, return all strings

Returns:

  • (Array<String>)

Raises:

  • (IndexError) —

    if offset is too great

  • (NullPointerError) —

    if memory not initialized


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# File 'ext/ffi_c/AbstractMemory.c', line 432

static VALUE
memory_get_array_of_string(int argc, VALUE* argv, VALUE self)
{
    VALUE offset = Qnil, countnum = Qnil, retVal = Qnil;
    AbstractMemory* ptr;
    long off;
    int count;

    rb_scan_args(argc, argv, "11", &offset, &countnum);
    off = NUM2LONG(offset);
    count = (countnum == Qnil ? 0 : NUM2INT(countnum));
    retVal = rb_ary_new2(count);

    Data_Get_Struct(self, AbstractMemory, ptr);
    checkRead(ptr);

    if (countnum != Qnil) {
        int i;

        checkBounds(ptr, off, count * sizeof (char*));

        for (i = 0; i < count; ++i) {
            const char* strptr = *((const char**) (ptr->address + off) + i);
            rb_ary_push(retVal, (strptr == NULL ? Qnil : rb_str_new2(strptr)));
        }

    } else {
        checkBounds(ptr, off, sizeof (char*));
        for ( ; off < ptr->size - (long) sizeof (void *); off += (long) sizeof (void *)) {
            const char* strptr = *(const char**) (ptr->address + off);
            if (strptr == NULL) {
                break;
            }
            rb_ary_push(retVal, rb_str_new2(strptr));
        }
    }

    return retVal;
}

#get_bytes(offset, length) ⇒ String

Return string contained in memory.

Parameters:

  • offset (Numeric) —

    point in buffer to start from

  • length (Numeric) —

    string's length in bytes.

Returns:

  • (String)

Raises:

  • (IndexError) —

    if length is too great

  • (NullPointerError) —

    if memory not initialized


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# File 'ext/ffi_c/AbstractMemory.c', line 532

static VALUE
memory_get_bytes(VALUE self, VALUE offset, VALUE length)
{
    AbstractMemory* ptr = MEMORY(self);
    long off, len;

    off = NUM2LONG(offset);
    len = NUM2LONG(length);

    checkRead(ptr);
    checkBounds(ptr, off, len);

    return rb_str_new((char *) ptr->address + off, len);
}

#get_float32(offset) ⇒ Float Also known as: get_float

Get a 32-bit float from memory at offset offset (alias: #get_float).

Parameters:

  • offset (Numeric)

Returns:

  • (Float)

#get_float64(offset) ⇒ Float Also known as: get_double

Get a 64-bit float (double) from memory at offset offset (alias: #get_double).

Parameters:

  • offset (Numeric)

Returns:

  • (Float)

#get_pointer(offset) ⇒ Pointer

Get a Pointer to the memory from offset.

Parameters:

  • offset (Numeric)

Returns:

#get_string(offset, length = nil) ⇒ String

Return string contained in memory.

Parameters:

  • offset (Numeric) —

    point in buffer to start from

  • length (Numeric) —

    string's length in bytes. If nil, a (memory size - offset) length string is returned).

Returns:

  • (String)

Raises:

  • (IndexError) —

    if length is too great

  • (NullPointerError) —

    if memory not initialized


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# File 'ext/ffi_c/AbstractMemory.c', line 404

static VALUE
memory_get_string(int argc, VALUE* argv, VALUE self)
{
    VALUE length = Qnil, offset = Qnil;
    AbstractMemory* ptr = MEMORY(self);
    long off, len;
    char* end;
    int nargs = rb_scan_args(argc, argv, "11", &offset, &length);

    off = NUM2LONG(offset);
    len = nargs > 1 && length != Qnil ? NUM2LONG(length) : (ptr->size - off);
    checkRead(ptr);
    checkBounds(ptr, off, len);

    end = memchr(ptr->address + off, 0, len);
    return rb_str_new((char *) ptr->address + off,
            (end != NULL ? end - ptr->address - off : len));
}

#put(type, offset, value) ⇒ nil

Parameters:

  • type_name (Symbol, Type) —

    type of data to put

  • offset (Numeric) —

    point in buffer to start from

Returns:

  • (nil)

Raises:

  • (ArgumentError) —

    if type is not supported


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# File 'ext/ffi_c/AbstractMemory.c', line 369

static VALUE
memory_put(VALUE self, VALUE type_name, VALUE offset, VALUE value)
{
    AbstractMemory* ptr;
    VALUE nType;
    Type *type;

    nType = rbffi_Type_Lookup(type_name);
    if(NIL_P(nType)) goto undefined_type;

    Data_Get_Struct(self, AbstractMemory, ptr);
    Data_Get_Struct(nType, Type, type);

    MemoryOp *op = get_memory_op(type);
    if(op == NULL) goto undefined_type;

    op->put(ptr, NUM2LONG(offset), value);
    return Qnil;

undefined_type: {
    VALUE msg = rb_sprintf("unsupported type '%" PRIsVALUE "'", type_name);
    rb_exc_raise(rb_exc_new3(rb_eArgError, msg));
    return Qnil;
  }
}

#put_array_of_float32(offset, ary) ⇒ self Also known as: put_array_of_float

Put values from ary as 32-bit floats in memory from offset offset (alias: #put_array_of_float).

Parameters:

  • offset (Numeric)
  • ary (Array<Numeric>)

Returns:

  • (self)

#put_array_of_float64(offset, ary) ⇒ self Also known as: put_array_of_double

Put values from ary as 64-bit floats (doubles) in memory from offset offset (alias: #put_array_of_double).

Parameters:

  • offset (Numeric)
  • ary (Array<Numeric>)

Returns:

  • (self)

#put_array_of_pointer(offset, ary) ⇒ self

Put an array of Pointer into memory from offset.

Parameters:

  • offset (Numeric)
  • ary (Array<#to_ptr>)

Returns:

  • (self)

#put_bytes(offset, str, index = 0, length = nil) ⇒ self

Put a string in memory.

Parameters:

  • offset (Numeric) —

    point in buffer to start from

  • str (String) —

    string to put to memory

  • index (Numeric)
  • length (Numeric) —

    string's length in bytes. If nil, a (memory size - offset) length string is returned).

Returns:

  • (self)

Raises:

  • (IndexError) —

    if length is too great

  • (NullPointerError) —

    if memory not initialized

  • (RangeError) —

    if index is negative, or if index+length is greater than size of string

  • (SecurityError) —

    when writing unsafe string to memory


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# File 'ext/ffi_c/AbstractMemory.c', line 560

static VALUE
memory_put_bytes(int argc, VALUE* argv, VALUE self)
{
    AbstractMemory* ptr = MEMORY(self);
    VALUE offset = Qnil, str = Qnil, rbIndex = Qnil, rbLength = Qnil;
    long off, len, idx;
    int nargs = rb_scan_args(argc, argv, "22", &offset, &str, &rbIndex, &rbLength);

    Check_Type(str, T_STRING);

    off = NUM2LONG(offset);
    idx = nargs > 2 ? NUM2LONG(rbIndex) : 0;
    if (idx < 0) {
        rb_raise(rb_eRangeError, "index cannot be less than zero");
        return Qnil;
    }
    len = nargs > 3 ? NUM2LONG(rbLength) : (RSTRING_LEN(str) - idx);
    if ((idx + len) > RSTRING_LEN(str)) {
        rb_raise(rb_eRangeError, "index+length is greater than size of string");
        return Qnil;
    }

    checkWrite(ptr);
    checkBounds(ptr, off, len);

    memcpy(ptr->address + off, RSTRING_PTR(str) + idx, len);

    return self;
}

#put_float32offset ⇒ self Also known as: put_float

Put value as a 32-bit float in memory at offset offset (alias: #put_float).

Parameters:

  • offset (Numeric)
  • value (Numeric)

Returns:

  • (self)

#put_float64(offset, value) ⇒ self Also known as: put_double

Put value as a 64-bit float (double) in memory at offset offset (alias: #put_double).

Parameters:

  • offset (Numeric)
  • value (Numeric)

Returns:

  • (self)

#put_pointer(offset, value) ⇒ self

Put value in memory from offset..

Parameters:

  • offset (Numeric)
  • value (nil, Pointer, Integer, #to_ptr)

Returns:

  • (self)

#put_string(offset, str) ⇒ self

Put a string in memory.

Parameters:

  • offset (Numeric)
  • str (String)

Returns:

  • (self)

Raises:

  • (SecurityError) —

    when writing unsafe string to memory

  • (IndexError) —

    if offset is too great

  • (NullPointerError) —

    if memory not initialized


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# File 'ext/ffi_c/AbstractMemory.c', line 504

static VALUE
memory_put_string(VALUE self, VALUE offset, VALUE str)
{
    AbstractMemory* ptr = MEMORY(self);
    long off, len;

    Check_Type(str, T_STRING);
    off = NUM2LONG(offset);
    len = RSTRING_LEN(str);

    checkWrite(ptr);
    checkBounds(ptr, off, len + 1);

    memcpy(ptr->address + off, RSTRING_PTR(str), len);
    *((char *) ptr->address + off + len) = '\0';

    return self;
}

#read_array_of_double(length) ⇒ Array<Float>

Read 64-bit floats (doubles) from memory.

Same as:

memory.get_array_of_double(0, ary)

Parameters:

  • length (Numeric) —

    number of Float to read

Returns:

  • (Array<Float>)

#read_array_of_float(length) ⇒ Array<Float>

Read 32-bit floats from memory.

Same as:

memory.get_array_of_float(0, ary)

Parameters:

  • length (Numeric) —

    number of Float to read

Returns:

  • (Array<Float>)

#read_array_of_pointer(length) ⇒ Array<Pointer>

Read an array of Pointer of length length.

Same as:

memory.get_array_of_pointer(0, length)

Parameters:

  • length (Numeric)

Returns:

#read_bytes(length) ⇒ String

equivalent to :

memory.get_bytes(0, length)

Parameters:

  • length (Numeric) —

    of string to return

Returns:

  • (String) 

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# File 'ext/ffi_c/AbstractMemory.c', line 597

static VALUE
memory_read_bytes(VALUE self, VALUE length)
{
    return memory_get_bytes(self, INT2FIX(0), length);
}

#read_double ⇒ Float

Read a 64-bit float (double) from memory.

Same as:

memory.get_double(0)

Returns:

  • (Float)

#read_float ⇒ Float

Read a 32-bit float from memory.

Same as:

memory.get_float(0)

Returns:

  • (Float)

#read_pointer ⇒ Pointer

Get a Pointer to the memory from base address.

Equivalent to:

memory.get_pointer(0)

Returns:

#size_limit? ⇒ Boolean

Return true if self has a size limit.

Returns:

  • (Boolean) 

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# File 'lib/ffi/abstract_memory.rb', line 40

def size_limit?
  size != LONG_MAX
end

#size ⇒ Numeric Also known as: size

Return memory size in bytes (alias: #total)

Returns:

  • (Numeric) 

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# File 'ext/ffi_c/AbstractMemory.c', line 319

static VALUE
memory_size(VALUE self)
{
    AbstractMemory* ptr;

    Data_Get_Struct(self, AbstractMemory, ptr);

    return LONG2NUM(ptr->size);
}

#type_size ⇒ Numeric

Get the memory's type size.

Returns:

  • (Numeric) —

    type size in bytes


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# File 'ext/ffi_c/AbstractMemory.c', line 631

static VALUE
memory_type_size(VALUE self)
{
    AbstractMemory* ptr;

    Data_Get_Struct(self, AbstractMemory, ptr);

    return INT2NUM(ptr->typeSize);
}

#write_array_of_double(ary) ⇒ self

Write values from ary as 64-bit floats (doubles) in memory.

Same as:

memory.put_array_of_double(0, ary)

Parameters:

  • ary (Array<Numeric>)

Returns:

  • (self)

#write_array_of_float(ary) ⇒ self

Write values from ary as 32-bit floats in memory.

Same as:

memory.put_array_of_float(0, ary)

Parameters:

  • ary (Array<Numeric>)

Returns:

  • (self)

#write_array_of_pointer(ary) ⇒ self

Write an array of Pointer into memory from offset.

Same as :

memory.put_array_of_pointer(0, ary)

Parameters:

  • ary (Array<#to_ptr>)

Returns:

  • (self)

#write_bytes(str, index = 0, length = nil) ⇒ self

equivalent to :

memory.put_bytes(0, str, index, length)

Parameters:

  • str (String) —

    string to put to memory

  • index (Numeric)
  • length (Numeric) —

    string's length in bytes. If nil, a (memory size - offset) length string is returned).

Returns:

  • (self) 

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# File 'ext/ffi_c/AbstractMemory.c', line 612

static VALUE
memory_write_bytes(int argc, VALUE* argv, VALUE self)
{
    VALUE* wargv = ALLOCA_N(VALUE, argc + 1);
    int i;

    wargv[0] = INT2FIX(0);
    for (i = 0; i < argc; i++) {
        wargv[i + 1] = argv[i];
    }

    return memory_put_bytes(argc + 1, wargv, self);
}

#write_double(value) ⇒ self

Write value as a 64-bit float (double) in memory.

Same as:

memory.put_double(0, value)

Parameters:

  • value (Numeric)

Returns:

  • (self)

#write_float(value) ⇒ self

Write value as a 32-bit float in memory.

Same as:

memory.put_float(0, value)

Parameters:

  • value (Numeric)

Returns:

  • (self)

#write_pointer(value) ⇒ self

Write value in memory.

Equivalent to:

memory.put_pointer(0, value)

Parameters:

  • value (nil, Pointer, Integer, #to_ptr)

Returns:

  • (self)