Module: PWN::FFI::Volk

Extended by:
Library
Defined in:
lib/pwn/ffi/volk.rb

Overview

Thin VOLK (Vector-Optimized Library of Kernels) binding.

Dispatches to SIMD kernels (SSE/AVX/NEON/…) when the host provides them. Used by PWN::SDR::Decoder::DSP hot paths so MHz-rate I/Q work stays off the Ruby GC heap while orchestration remains pure Ruby.

Nothing here shells out and nothing is compiled at gem-install time — if libvolk is missing, .available? is false and callers fall back.

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.load_error ⇒ Object (readonly)

Returns the value of attribute load_error.



28
29
30
 
# File 'lib/pwn/ffi/volk.rb', line 28

def load_error
  @load_error
end

Class Method Details

.accumulate(opts = {}) ⇒ Object

Supported Method Parameters

sum = PWN::FFI::Volk.accumulate(samples: Array)



82
83
84
85
86
87
88
89
90
91
92
93
 
# File 'lib/pwn/ffi/volk.rb', line 82

public_class_method def self.accumulate(opts = {})
  raise 'ERROR: libvolk not available' unless available?

  samples = opts[:samples]
  n = samples.length
  return 0.0 if n.zero?

  in_ptr = float_ptr(samples)
  out_ptr = PubFFI::MemoryPointer.new(:float, 1)
  accum_fn.call(out_ptr, in_ptr, n)
  out_ptr.read_float
end

.authors ⇒ Object

Author(s)

0day Inc. [email protected]



168
169
170
 
# File 'lib/pwn/ffi/volk.rb', line 168

public_class_method def self.authors
  "AUTHOR(S):\n  0day Inc. <[email protected]>\n"
end

.available? ⇒ Boolean

Supported Method Parameters

PWN::FFI::Volk.available?

Returns:

  • (Boolean) 


51
52
53
54
55
 
# File 'lib/pwn/ffi/volk.rb', line 51

public_class_method def self.available?
  !@load_error && respond_to?(:volk_get_alignment, true)
rescue StandardError
  false
end

.dot_prod(opts = {}) ⇒ Object

Supported Method Parameters

sum = PWN::FFI::Volk.dot_prod(a: Array, b: Array)



151
152
153
154
155
156
157
158
159
160
161
162
163
164
 
# File 'lib/pwn/ffi/volk.rb', line 151

public_class_method def self.dot_prod(opts = {})
  raise 'ERROR: libvolk not available' unless available?

  a = opts[:a]
  b = opts[:b]
  n = [a.length, b.length].min
  return 0.0 if n.zero?

  a_ptr = float_ptr(a)
  b_ptr = float_ptr(b)
  out_ptr = PubFFI::MemoryPointer.new(:float, 1)
  dot_fn.call(out_ptr, a_ptr, b_ptr, n)
  out_ptr.read_float
end

.help ⇒ Object

Display Usage for this Module



174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
 
# File 'lib/pwn/ffi/volk.rb', line 174

public_class_method def self.help
  puts "USAGE:
    # Run available and return its result
    #{self}.available?

    # Run unpack s16le and return its result
    #{self}.unpack_s16le(
      data: 'required - raw String of little-endian signed 16-bit PCM'
    )

    # Run accumulate and return its result
    #{self}.accumulate(
      samples: 'optional - samples value consumed by #accumulate'
    )

    # Run magnitude squared and return its result
    #{self}.magnitude_squared(
      iq: 'required - Array of interleaved I/Q Floats (even length)'
    )

    # Run sqrt and return its result
    #{self}.sqrt(
      samples: 'optional - samples value consumed by #sqrt'
    )

    # Run scale and return its result
    #{self}.scale(
      samples: 'optional - samples value consumed by #scale',
      factor: 'optional - factor value consumed by #scale'
    )

    # Run dot prod and return its result
    #{self}.dot_prod(
      a: 'required - a value consumed by #dot_prod',
      b: 'required - b value consumed by #dot_prod'
    )

    # Print the AUTHOR(S) string for this module.
    #{self}.authors
  "
  constants.sort
end

.magnitude_squared(opts = {}) ⇒ Object

Supported Method Parameters

power = PWN::FFI::Volk.magnitude_squared( iq: 'required - Array of interleaved I/Q Floats (even length)' ) Returns Array of |z|^2 per complex sample.



101
102
103
104
105
106
107
108
109
110
111
112
 
# File 'lib/pwn/ffi/volk.rb', line 101

public_class_method def self.magnitude_squared(opts = {})
  raise 'ERROR: libvolk not available' unless available?

  iq = opts[:iq]
  n_c = iq.length / 2
  return [] if n_c.zero?

  in_ptr = float_ptr(iq)
  out_ptr = PubFFI::MemoryPointer.new(:float, n_c)
  mag2_fn.call(out_ptr, in_ptr, n_c)
  out_ptr.read_array_of_float(n_c)
end

.scale(opts = {}) ⇒ Object

Supported Method Parameters

out = PWN::FFI::Volk.scale(samples: Array, factor: Float) Multiplies every sample by factor.



134
135
136
137
138
139
140
141
142
143
144
145
146
 
# File 'lib/pwn/ffi/volk.rb', line 134

public_class_method def self.scale(opts = {})
  raise 'ERROR: libvolk not available' unless available?

  samples = opts[:samples]
  factor  = opts[:factor].to_f
  n = samples.length
  return [] if n.zero?

  in_ptr = float_ptr(samples)
  out_ptr = PubFFI::MemoryPointer.new(:float, n)
  scale_fn.call(out_ptr, in_ptr, factor, n)
  out_ptr.read_array_of_float(n)
end

.sqrt(opts = {}) ⇒ Object

Supported Method Parameters

out = PWN::FFI::Volk.sqrt(samples: Array)



117
118
119
120
121
122
123
124
125
126
127
128
 
# File 'lib/pwn/ffi/volk.rb', line 117

public_class_method def self.sqrt(opts = {})
  raise 'ERROR: libvolk not available' unless available?

  samples = opts[:samples]
  n = samples.length
  return [] if n.zero?

  in_ptr = float_ptr(samples)
  out_ptr = PubFFI::MemoryPointer.new(:float, n)
  sqrt_fn.call(out_ptr, in_ptr, n)
  out_ptr.read_array_of_float(n)
end

.unpack_s16le(opts = {}) ⇒ Object

Supported Method Parameters

samples = PWN::FFI::Volk.unpack_s16le( data: 'required - raw String of little-endian signed 16-bit PCM' ) Returns Array normalised to -1.0..1.0 (same contract as PWN::SDR::Decoder::DSP.unpack_s16le). VOLK treats scalar as a divisor, so pass 32768.0 to get unit-range floats.



65
66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/pwn/ffi/volk.rb', line 65

public_class_method def self.unpack_s16le(opts = {})
  raise 'ERROR: libvolk not available' unless available?

  data = opts[:data].to_s
  n = data.bytesize / 2
  return [] if n.zero?

  in_ptr = PubFFI::MemoryPointer.from_string(data)
  # from_string null-terminates — reclaim only the payload region
  out_ptr = PubFFI::MemoryPointer.new(:float, n)
  convert_fn.call(out_ptr, in_ptr, 32_768.0, n)
  out_ptr.read_array_of_float(n)
end