fft: Add fft_shift class

This is a generic FFT shift object. Includes C++ unit tests. The class is templated and thus works with FFTs of any type.
author: Christoph Mayer <hcab14@gmail.com> 2019-05-23 10:58:51 +0000
committer: Martin Braun <martin.braun@ettus.com> 2019-06-15 17:17:02 -0700
commit: 6996d1b7ee20fb7611068906bb64886eb5b514ef (patch)
tree: d121f1ba55aaea456906aca4f46c66b0be83bf6e
parent: 565d133ff028b316a9d920e631df0bd38cd7bd1e (diff)
12 files changed, 199 insertions, 73 deletions
diff --git a/gr-fft/include/gnuradio/fft/CMakeLists.txt b/gr-fft/include/gnuradio/fft/CMakeLists.txt
index 0f52b0aa96..2bd77b8d3c 100644
--- a/gr-fft/include/gnuradio/fft/CMakeLists.txt
+++ b/gr-fft/include/gnuradio/fft/CMakeLists.txt
@@ -23,6 +23,7 @@
 install(FILES
     api.h
     fft.h
+    fft_shift.h
     fft_vcc.h
     fft_vfc.h
     goertzel.h
diff --git a/gr-fft/include/gnuradio/fft/fft_shift.h b/gr-fft/include/gnuradio/fft/fft_shift.h
new file mode 100644
index 0000000000..1ee08915b9
--- /dev/null
+++ b/gr-fft/include/gnuradio/fft/fft_shift.h
@@ -0,0 +1,82 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2019 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_FFT_FFT_SHIFT_H
+#define INCLUDED_FFT_FFT_SHIFT_H
+
+#include <algorithm>
+#include <cassert>
+#include <vector>
+
+namespace gr {
+namespace fft {
+
+  /*! \brief reorder FFT results which are ordered from 0 to 1 in normalized frequency
+   *  to -0.5 to 0.5 by cyclic shift
+   */
+  template<typename T>
+  class fft_shift {
+  public:
+    fft_shift(size_t fft_length)
+      : d_fftlen(fft_length)
+      , d_lenpos(fft_length/2 + (fft_length%2))
+      , d_lenneg(fft_length/2)
+      , d_buf(fft_length) {}
+
+    /*! performs the cyclic shift on a vector v
+     */
+    void shift(std::vector<T>& v) {
+      shift(&v.front(), v.size());
+    }
+
+    /*! performs the cyclic shift on an array
+     */
+    void shift(T* data, size_t fft_len) {
+      resize(fft_len);
+      std::copy_n(data,          d_lenpos, d_buf.begin());
+      std::copy_n(data+d_lenpos, d_lenneg, data);
+      std::copy_n(d_buf.begin(), d_lenpos, data+d_lenneg);
+    }
+
+    /*! if needed adjusts the buffer size to a new fft length
+     */
+    void resize(size_t fft_length) {
+      if (d_fftlen == fft_length)
+        return;
+      d_fftlen = fft_length;
+      d_lenpos = d_fftlen/2 + (d_fftlen%2);
+      d_lenneg = d_fftlen/2;
+      assert(d_lenpos + d_lenneg == d_fftlen);
+      d_buf.resize(d_lenpos);
+    }
+  protected:
+
+  private:
+    size_t d_fftlen;      // FFT length
+    size_t d_lenpos;      // number of FFT bins with positive frequencies
+    size_t d_lenneg;      // number of FFT bins with negative frequencies
+    std::vector<T> d_buf; // buffer used for cyclic shift
+  } ;
+
+} // namespace fft
+} // namespace gr
+#endif // INCLUDED_FFT_FFT_SHIFT_H
diff --git a/gr-fft/lib/CMakeLists.txt b/gr-fft/lib/CMakeLists.txt
index 7b8207665e..14541fcffc 100644
--- a/gr-fft/lib/CMakeLists.txt
+++ b/gr-fft/lib/CMakeLists.txt
@@ -65,3 +65,18 @@ endif(MSVC)
 if(BUILD_SHARED_LIBS)
   GR_LIBRARY_FOO(gnuradio-fft FFTW3f)
 endif()
+
+if(ENABLE_TESTING)
+  include(GrTest)
+
+  list(APPEND test_gr_fft_sources
+    qa_fft_shift
+  )
+  list(APPEND GR_TEST_TARGET_DEPS gnuradio-fft)
+
+  foreach(qa_file ${test_gr_fft_sources})
+    GR_ADD_CPP_TEST("fft_${qa_file}"
+      ${CMAKE_CURRENT_SOURCE_DIR}/${qa_file}
+    )
+  endforeach(qa_file)
+endif(ENABLE_TESTING)
diff --git a/gr-fft/lib/qa_fft_shift.cc b/gr-fft/lib/qa_fft_shift.cc
new file mode 100644
index 0000000000..e924af8629
--- /dev/null
+++ b/gr-fft/lib/qa_fft_shift.cc
@@ -0,0 +1,62 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2019 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gnuradio/fft/fft_shift.h>
+#include <boost/test/unit_test.hpp>
+#include <vector>
+
+namespace gr {
+namespace fft {
+
+BOOST_AUTO_TEST_CASE(t1)
+{
+  fft::fft_shift<int> s(1023);
+
+  std::vector<int> x_even{  0,  1,  2,  3, -4, -3, -2, -1 };
+  std::vector<int> y_even{ -4, -3, -2, -1,  0,  1,  2,  3 }; // expected result
+
+  s.shift(x_even);
+  BOOST_TEST(x_even == y_even, boost::test_tools::per_element());
+
+  // two shifts should not change the result
+  s.shift(x_even);
+  s.shift(x_even);
+  BOOST_TEST(x_even == y_even, boost::test_tools::per_element());
+}
+
+BOOST_AUTO_TEST_CASE(t2)
+{
+  fft::fft_shift<int> s(7);
+
+  std::vector<int> x_odd{  0,  1,  2, 3, -3, -2, -1 };
+  std::vector<int> y_odd{ -3, -2, -1, 0,  1,  2,  3 }; // expected result
+
+  s.shift(x_odd);
+  BOOST_TEST(x_odd == y_odd, boost::test_tools::per_element());
+}
+
+} /* namespace fft */
+} /* namespace gr */
diff --git a/gr-qtgui/lib/freq_sink_c_impl.cc b/gr-qtgui/lib/freq_sink_c_impl.cc
index e94dae6074..3f31c90975 100644
--- a/gr-qtgui/lib/freq_sink_c_impl.cc
+++ b/gr-qtgui/lib/freq_sink_c_impl.cc
@@ -59,7 +59,9 @@ namespace gr {
       : sync_block("freq_sink_c",
                    io_signature::make(0, nconnections, sizeof(gr_complex)),
                    io_signature::make(0, 0, 0)),
-	d_fftsize(fftsize), d_fftavg(1.0),
+	d_fftsize(fftsize),
+	d_fft_shift(fftsize),
+	d_fftavg(1.0),
 	d_wintype((filter::firdes::win_type)(wintype)),
   d_center_freq(fc), d_bandwidth(bw), d_name(name),
   d_nconnections(nconnections),
@@ -103,11 +105,6 @@ namespace gr {
                                    volk_get_alignment());
       memset(d_fbuf, 0, d_fftsize*sizeof(float));
 
-      d_tmpbuflen = (unsigned int)(floor(d_fftsize/2.0));
-      d_tmpbuf = (float*)volk_malloc(sizeof(float)*(d_tmpbuflen + 1),
-                                     volk_get_alignment());
-
-
       d_index = 0;
       // save the last "connection" for the PDU memory
       for(int i = 0; i < d_nconnections; i++) {
@@ -147,7 +144,6 @@ namespace gr {
       }
       delete d_fft;
       volk_free(d_fbuf);
-      volk_free(d_tmpbuf);
 
       delete d_argv;
     }
@@ -503,18 +499,7 @@ namespace gr {
       volk_32fc_s32f_x2_power_spectral_density_32f(data_out, d_fft->get_outbuf(),
                                                    size, 1.0, size);
 
-      // Perform shift operation
-      //  size=8, d_tmpbuflen=4:
-      //    freqs=[0.00000   0.12500   0.25000   0.37500  -0.50000  -0.37500  -0.25000  -0.12500]
-      //  size=7, d_tmpbuflen=3:
-      //    freqa=[0.00000   0.14286   0.28571   0.42857  -0.42857  -0.28571  -0.14286]
-      const int off = size%2;
-      const int len = d_tmpbuflen;
-      assert(len+off +  len == size);
-      //     | pos.|   |neg.| frequencies
-      std::copy_n(data_out,         len+off, d_tmpbuf);
-      std::copy_n(data_out+len+off, len,     data_out);
-      std::copy_n(d_tmpbuf,         len+off, data_out+len);
+      d_fft_shift.shift(data_out, size);
     }
 
     bool
@@ -585,10 +570,7 @@ namespace gr {
                                      volk_get_alignment());
 	memset(d_fbuf, 0, d_fftsize*sizeof(float));
 
-	volk_free(d_tmpbuf);
-        d_tmpbuflen = (unsigned int)(floor(d_fftsize/2.0));
-        d_tmpbuf = (float*)volk_malloc(sizeof(float)*(d_tmpbuflen + 1),
-                                       volk_get_alignment());
+	d_fft_shift.resize(d_fftsize);
 
         d_last_time = 0;
 
diff --git a/gr-qtgui/lib/freq_sink_c_impl.h b/gr-qtgui/lib/freq_sink_c_impl.h
index 842b525193..09f8eaf388 100644
--- a/gr-qtgui/lib/freq_sink_c_impl.h
+++ b/gr-qtgui/lib/freq_sink_c_impl.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2012,2015 Free Software Foundation, Inc.
+ * Copyright 2012,2015,2019 Free Software Foundation, Inc.
  *
  * This file is part of GNU Radio
  *
@@ -27,6 +27,7 @@
 
 #include <gnuradio/filter/firdes.h>
 #include <gnuradio/fft/fft.h>
+#include <gnuradio/fft/fft_shift.h>
 #include <gnuradio/high_res_timer.h>
 #include <gnuradio/qtgui/freqdisplayform.h>
 
@@ -39,7 +40,7 @@ namespace gr {
       void initialize();
 
       int d_fftsize;
-      int d_tmpbuflen;
+      fft::fft_shift<float> d_fft_shift;
       float d_fftavg;
       filter::firdes::win_type d_wintype;
       std::vector<float> d_window;
@@ -59,7 +60,6 @@ namespace gr {
       std::vector<double*> d_magbufs;
       double* d_pdu_magbuf;
       float *d_fbuf;
-      float *d_tmpbuf;
 
       int d_argc;
       char *d_argv;
diff --git a/gr-qtgui/lib/freq_sink_f_impl.cc b/gr-qtgui/lib/freq_sink_f_impl.cc
index 86ce4b2c4e..efc03f5f8e 100644
--- a/gr-qtgui/lib/freq_sink_f_impl.cc
+++ b/gr-qtgui/lib/freq_sink_f_impl.cc
@@ -37,6 +37,7 @@
 namespace gr {
   namespace qtgui {
 
+
     freq_sink_f::sptr
     freq_sink_f::make(int fftsize, int wintype,
 		      double fc, double bw,
@@ -59,7 +60,9 @@ namespace gr {
       : sync_block("freq_sink_f",
                    io_signature::make(0, nconnections, sizeof(float)),
                    io_signature::make(0, 0, 0)),
-	d_fftsize(fftsize), d_fftavg(1.0),
+	d_fftsize(fftsize),
+	d_fft_shift(fftsize),
+	d_fftavg(1.0),
 	d_wintype((filter::firdes::win_type)(wintype)),
 	d_center_freq(fc), d_bandwidth(bw), d_name(name),
   d_nconnections(nconnections),
@@ -103,10 +106,6 @@ namespace gr {
                                    volk_get_alignment());
       memset(d_fbuf, 0, d_fftsize*sizeof(float));
 
-      d_tmpbuflen = (unsigned int)(floor(d_fftsize/2.0));
-      d_tmpbuf = (float*)volk_malloc(sizeof(float)*(d_tmpbuflen + 1),
-                                     volk_get_alignment());
-
       d_index = 0;
       // save the last "connection" for the PDU memory
       for(int i = 0; i < d_nconnections; i++) {
@@ -146,7 +145,6 @@ namespace gr {
       }
       delete d_fft;
       volk_free(d_fbuf);
-      volk_free(d_tmpbuf);
 
       delete d_argv;
     }
@@ -508,14 +506,7 @@ namespace gr {
       volk_32fc_s32f_x2_power_spectral_density_32f(data_out, d_fft->get_outbuf(),
                                                    size, 1.0, size);
 
-      // Perform shift operation
-      const int off = size%2;
-      const int len = d_tmpbuflen;
-      assert(len+off +  len == size);
-      //     | pos.|   |neg.| frequencies
-      std::copy_n(data_out,         len+off, d_tmpbuf);
-      std::copy_n(data_out+len+off, len,     data_out);
-      std::copy_n(d_tmpbuf,         len+off, data_out+len);
+      d_fft_shift.shift(data_out, size);
     }
 
     bool
@@ -586,10 +577,7 @@ namespace gr {
                                      volk_get_alignment());
 	memset(d_fbuf, 0, d_fftsize*sizeof(float));
 
-	volk_free(d_tmpbuf);
-        d_tmpbuflen = (unsigned int)(floor(d_fftsize/2.0));
-        d_tmpbuf = (float*)volk_malloc(sizeof(float)*(d_tmpbuflen + 1),
-                                       volk_get_alignment());
+	d_fft_shift.resize(d_fftsize);
 
         d_last_time = 0;
 
diff --git a/gr-qtgui/lib/freq_sink_f_impl.h b/gr-qtgui/lib/freq_sink_f_impl.h
index 9b656f6e57..4214943c73 100644
--- a/gr-qtgui/lib/freq_sink_f_impl.h
+++ b/gr-qtgui/lib/freq_sink_f_impl.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2012,2014-2015 Free Software Foundation, Inc.
+ * Copyright 2012,2014-2015,2019 Free Software Foundation, Inc.
  *
  * This file is part of GNU Radio
  *
@@ -27,6 +27,7 @@
 
 #include <gnuradio/filter/firdes.h>
 #include <gnuradio/fft/fft.h>
+#include <gnuradio/fft/fft_shift.h>
 #include <gnuradio/high_res_timer.h>
 #include <gnuradio/qtgui/freqdisplayform.h>
 
@@ -39,7 +40,7 @@ namespace gr {
       void initialize();
 
       int d_fftsize;
-      int d_tmpbuflen;
+      fft::fft_shift<float> d_fft_shift;
       float d_fftavg;
       filter::firdes::win_type d_wintype;
       std::vector<float> d_window;
@@ -59,7 +60,6 @@ namespace gr {
       std::vector<double*> d_magbufs;
       double* d_pdu_magbuf;
       float *d_fbuf;
-      float *d_tmpbuf;
 
       int d_argc;
       char *d_argv;
diff --git a/gr-qtgui/lib/waterfall_sink_c_impl.cc b/gr-qtgui/lib/waterfall_sink_c_impl.cc
index cf178eadb2..eac4badce5 100644
--- a/gr-qtgui/lib/waterfall_sink_c_impl.cc
+++ b/gr-qtgui/lib/waterfall_sink_c_impl.cc
@@ -60,7 +60,9 @@ namespace gr {
       : sync_block("waterfall_sink_c",
                    io_signature::make(0, nconnections, sizeof(gr_complex)),
                    io_signature::make(0, 0, 0)),
-	d_fftsize(fftsize), d_fftavg(1.0),
+	d_fftsize(fftsize),
+	d_fft_shift(fftsize),
+	d_fftavg(1.0),
 	d_wintype((filter::firdes::win_type)(wintype)),
     d_center_freq(fc),
     d_bandwidth(bw),
@@ -116,7 +118,7 @@ namespace gr {
       // setup bw input port
       message_port_register_in(d_port_bw);
       set_msg_handler(d_port_bw,
-                      boost::bind(&waterfall_sink_c_impl::handle_set_bw, this, _1));   
+                      boost::bind(&waterfall_sink_c_impl::handle_set_bw, this, _1));
 
       // setup output message port to post frequency when display is
       // double-clicked
@@ -405,15 +407,7 @@ namespace gr {
       volk_32fc_s32f_x2_power_spectral_density_32f(data_out, d_fft->get_outbuf(),
                                                    size, 1.0, size);
 
-      // Perform shift operation
-      const int len = (unsigned int)(floor(size/2.0));
-      const int off = size%2;
-      assert(len+off +   len    == size);
-      //     | pos.|   |neg.| frequencies
-      const std::vector<float> tmp(data_out, data_out+len+off);
-      // std::copy_n(data_out,      len+off, tmp.begin());
-      std::copy_n(data_out+len+off, len,     data_out);
-      std::copy_n(tmp.begin(),      len+off, data_out+len);
+      d_fft_shift.shift(data_out, size);
     }
 
     void
@@ -487,6 +481,8 @@ namespace gr {
         delete d_fft;
         d_fft = new fft::fft_complex(d_fftsize, true);
 
+	d_fft_shift.resize(d_fftsize);
+
         volk_free(d_fbuf);
         d_fbuf = (float*)volk_malloc(d_fftsize*sizeof(float),
                                      volk_get_alignment());
@@ -531,7 +527,7 @@ namespace gr {
                                     new SetFreqEvent(d_center_freq, d_bandwidth));
         }
       }
-    }        
+    }
 
     void
     waterfall_sink_c_impl::set_time_per_fft(double t)
diff --git a/gr-qtgui/lib/waterfall_sink_c_impl.h b/gr-qtgui/lib/waterfall_sink_c_impl.h
index e0d421e36b..6eba6f8ede 100644
--- a/gr-qtgui/lib/waterfall_sink_c_impl.h
+++ b/gr-qtgui/lib/waterfall_sink_c_impl.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2012,2015 Free Software Foundation, Inc.
+ * Copyright 2012,2015,2019 Free Software Foundation, Inc.
  *
  * This file is part of GNU Radio
  *
@@ -27,6 +27,7 @@
 
 #include <gnuradio/filter/firdes.h>
 #include <gnuradio/fft/fft.h>
+#include <gnuradio/fft/fft_shift.h>
 #include <gnuradio/high_res_timer.h>
 #include <gnuradio/qtgui/waterfalldisplayform.h>
 
@@ -41,6 +42,7 @@ namespace gr {
       void initialize();
 
       int d_fftsize;
+      fft::fft_shift<float> d_fft_shift;
       float d_fftavg;
       filter::firdes::win_type d_wintype;
       std::vector<float> d_window;
diff --git a/gr-qtgui/lib/waterfall_sink_f_impl.cc b/gr-qtgui/lib/waterfall_sink_f_impl.cc
index b93a5663aa..ad466b7c17 100644
--- a/gr-qtgui/lib/waterfall_sink_f_impl.cc
+++ b/gr-qtgui/lib/waterfall_sink_f_impl.cc
@@ -59,7 +59,9 @@ namespace gr {
       : sync_block("waterfall_sink_f",
                    io_signature::make(0, nconnections, sizeof(float)),
                    io_signature::make(0, 0, 0)),
-	d_fftsize(fftsize), d_fftavg(1.0),
+	d_fftsize(fftsize),
+	d_fft_shift(fftsize),
+	d_fftavg(1.0),
 	d_wintype((filter::firdes::win_type)(wintype)),
 	d_center_freq(fc), d_bandwidth(bw), d_name(name),
 	d_nconnections(nconnections), d_nrows(200),
@@ -112,7 +114,7 @@ namespace gr {
       // setup bw input port
       message_port_register_in(d_port_bw);
       set_msg_handler(d_port_bw,
-                      boost::bind(&waterfall_sink_f_impl::handle_set_bw, this, _1));   
+                      boost::bind(&waterfall_sink_f_impl::handle_set_bw, this, _1));
 
       // setup output message port to post frequency when display is
       // double-clicked
@@ -409,15 +411,7 @@ namespace gr {
       volk_32fc_s32f_x2_power_spectral_density_32f(data_out, d_fft->get_outbuf(),
                                                    size, 1.0, size);
 
-      // Perform shift operation
-      const int len = (int)(floor(size/2.0));
-      const int off = size%2;
-      assert(len+off +   len    == size);
-      //     | pos.|   |neg.| frequencies
-      const std::vector<float> tmp(data_out, data_out+len+off);
-      // std::copy_n(data_out,      len+off, tmp.begin());
-      std::copy_n(data_out+len+off, len,     data_out);
-      std::copy_n(tmp.begin(),      len+off, data_out+len);
+      d_fft_shift.shift(data_out, size);
     }
 
     void
@@ -491,6 +485,8 @@ namespace gr {
 	delete d_fft;
 	d_fft = new fft::fft_complex(d_fftsize, true);
 
+	d_fft_shift.resize(d_fftsize);
+
 	volk_free(d_fbuf);
 	d_fbuf = (float*)volk_malloc(d_fftsize*sizeof(float),
                                      volk_get_alignment());
@@ -535,7 +531,7 @@ namespace gr {
                                     new SetFreqEvent(d_center_freq, d_bandwidth));
         }
       }
-    }    
+    }
 
     void
     waterfall_sink_f_impl::set_time_per_fft(double t)
diff --git a/gr-qtgui/lib/waterfall_sink_f_impl.h b/gr-qtgui/lib/waterfall_sink_f_impl.h
index aca87b187a..d474a4f079 100644
--- a/gr-qtgui/lib/waterfall_sink_f_impl.h
+++ b/gr-qtgui/lib/waterfall_sink_f_impl.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2012,2015 Free Software Foundation, Inc.
+ * Copyright 2012,2015,2019 Free Software Foundation, Inc.
  *
  * This file is part of GNU Radio
  *
@@ -27,6 +27,7 @@
 
 #include <gnuradio/filter/firdes.h>
 #include <gnuradio/fft/fft.h>
+#include <gnuradio/fft/fft_shift.h>
 #include <gnuradio/high_res_timer.h>
 #include <gnuradio/qtgui/waterfalldisplayform.h>
 
@@ -41,6 +42,7 @@ namespace gr {
       void initialize();
 
       int d_fftsize;
+      fft::fft_shift<float> d_fft_shift;
       float d_fftavg;
       filter::firdes::win_type d_wintype;
       std::vector<float> d_window;
author	Christoph Mayer <hcab14@gmail.com>	2019-05-23 10:58:51 +0000
committer	Martin Braun <martin.braun@ettus.com>	2019-06-15 17:17:02 -0700
commit	6996d1b7ee20fb7611068906bb64886eb5b514ef (patch)
tree	d121f1ba55aaea456906aca4f46c66b0be83bf6e
parent	565d133ff028b316a9d920e631df0bd38cd7bd1e (diff)