instance.c: Fix a memory leak reported by scan-build.

[libsigrokdecode.git] / decoders / pwm / pd.py

diff --git a/decoders/pwm/pd.py b/decoders/pwm/pd.py
index a2fbb0fe26df4b0419e5c0c17b3438f61bedf870..97704450b7701f5a01387f234eea6e9d16cc0a8e 100644 (file)
--- a/decoders/pwm/pd.py
+++ b/decoders/pwm/pd.py
@@ -20,6 +20,9 @@
 
 import sigrokdecode as srd
 
+class SamplerateError(Exception):
+    pass
+
 class Decoder(srd.Decoder):
     api_version = 3
     id = 'pwm'
@@ -49,12 +52,11 @@ class Decoder(srd.Decoder):
     )
 
     def __init__(self):
+        self.reset()
+
+    def reset(self):
+        self.samplerate = None
         self.ss_block = self.es_block = None
-        self.first_samplenum = None
-        self.start_samplenum = None
-        self.end_samplenum = None
-        self.num_cycles = 0
-        self.average = 0
 
     def metadata(self, key, value):
         if key == srd.SRD_CONF_SAMPLERATE:
@@ -88,9 +90,14 @@ class Decoder(srd.Decoder):
         self.put(self.ss_block, self.es_block, self.out_ann, [1, [period_s]])
 
     def putb(self, data):
-        self.put(self.num_cycles, self.num_cycles, self.out_binary, data)
+        self.put(self.ss_block, self.es_block, self.out_binary, data)
 
     def decode(self):
+        if not self.samplerate:
+            raise SamplerateError('Cannot decode without samplerate.')
+
+        num_cycles = 0
+        average = 0
 
         # Wait for an "active" edge (depends on config). This starts
         # the first full period of the inspected signal waveform.
@@ -103,16 +110,16 @@ class Decoder(srd.Decoder):
 
             # Get the next two edges. Setup some variables that get
             # referenced in the calculation and in put() routines.
-            self.start_samplenum = self.samplenum
-            pins = self.wait({0: 'e'})
-            self.end_samplenum = self.samplenum
-            pins = self.wait({0: 'e'})
-            self.ss_block = self.start_samplenum
+            start_samplenum = self.samplenum
+            self.wait({0: 'e'})
+            end_samplenum = self.samplenum
+            self.wait({0: 'e'})
+            self.ss_block = start_samplenum
             self.es_block = self.samplenum
 
             # Calculate the period, the duty cycle, and its ratio.
-            period = self.samplenum - self.start_samplenum
-            duty = self.end_samplenum - self.start_samplenum
+            period = self.samplenum - start_samplenum
+            duty = end_samplenum - start_samplenum
             ratio = float(duty / period)
 
             # Report the duty cycle in percent.
@@ -127,7 +134,7 @@ class Decoder(srd.Decoder):
             self.putp(period_t)
 
             # Update and report the new duty cycle average.
-            self.num_cycles += 1
-            self.average += percent
+            num_cycles += 1
+            average += percent
             self.put(self.first_samplenum, self.es_block, self.out_average,
-                     float(self.average / self.num_cycles))
+                     float(average / num_cycles))