From: Christian Herdtweck <christian.herdtweck@intra2net.com>
Date: Tue, 12 Jan 2016 12:25:29 +0000 (+0100)
Subject: more renaming and testing to make clear CircularBuffer is not just for log text
X-Git-Tag: v1.2~85
X-Git-Url: http://developer.intra2net.com/git/?a=commitdiff_plain;h=e14eed4a563ff34b46db0da657fa18859fd92adb;p=pyi2ncommon

more renaming and testing to make clear CircularBuffer is not just for log text
---

diff --git a/buffers.py b/buffers.py
index 96e065d..bda7d80 100644
--- a/buffers.py
+++ b/buffers.py
@@ -29,36 +29,52 @@ Featuring::
 """
 
 class CircularBuffer:
-    """ circular buffer for text lines; saves last N lines
+    """ circular buffer for data; saves last N sets
     
-    can output them afterwards in correct order
+    can return or run func on them afterwards in correct order
 
-    public attributes (please read only!): buffer_size, n_lines
+    public attributes (please read only!): buffer_size, n_items
     """
 
     buffer_size = None
     _buffer = None
     _buff_idx = None
-    n_lines = None
+    n_items = None
 
-    def __init__(self, size):
+    def __init__(self, size, empty_element=None):
         """ initialize with N = size """
+        if size < 1:
+            raise ValueError('size must be positive!')
         self.buffer_size = size
-        self._buffer = ['[no output]' for line_idx in range(size)]
+        self._buffer = [empty_element for idx in range(size)]
         self._buff_idx = 0
-        self.n_lines = 0
+        self.n_items = 0
 
-    def add(self, line):
-        """ add a line to buffer -- might replace the oldest line """
-        self._buffer[self._buff_idx] = line
+    def add(self, new_item):
+        """ add a new item to buffer -- might replace the oldest item """
+        oldest_item = self._buffer[self._buff_idx]
+        self._buffer[self._buff_idx] = new_item
         self._buff_idx = (self._buff_idx + 1) % self.buffer_size
-        self.n_lines += 1
+        self.n_items += 1
+        return oldest_item
 
-    def output(self, output_func):
-        """ run output_func(line) on last saved lines """
-        if self.n_lines >= self.buffer_size:
+    def run_func(self, some_func):
+        """ run some_func(item) on last saved items in correct order """
+        if self.n_items >= self.buffer_size:
             for idx in range(self._buff_idx, self.buffer_size):
-                output_func(self._buffer[idx])
+                some_func(self._buffer[idx])
 
         for idx in range(0, self._buff_idx):
-            output_func(self._buffer[idx])
+            some_func(self._buffer[idx])
+
+    def get_all(self):
+        """ return the buffered contents in correct order """
+        result = []
+        if self.n_items >= self.buffer_size:
+            for idx in range(self._buff_idx, self.buffer_size):
+                result.append(self._buffer[idx])
+
+        for idx in range(0, self._buff_idx):
+            result.append(self._buffer[idx])
+
+        return result