Created images.py and moved image generation code to that file

Added more validation for width and height keys in
validate_results_request.
Fixed a small code issue in validate_results_request.

Author: catalin-manciu

codespeed/images.py

@@ -0,0 +1,70 @@
+import cStringIO
+from matplotlib.figure import Figure
+from matplotlib.ticker import FormatStrFormatter
+from matplotlib.backends.backend_agg import FigureCanvasAgg
+
+DEF_CHART_W = 600
+DEF_CHART_H = 500
+
+MIN_CHART_W = 400
+MIN_CHART_H = 300
+
+
+def gen_image_from_results(result_data, width, height):
+    canvas_width = width if width is not None else DEF_CHART_W
+    canvas_height = height if height is not None else DEF_CHART_H
+
+    canvas_width = max(canvas_width, MIN_CHART_W)
+    canvas_height = max(canvas_height, MIN_CHART_H)
+
+    values = [element.value for element in result_data['results']]
+
+    max_value = max(values)
+    min_value = min(values)
+    value_range = max_value - min_value
+    range_increment = 0.05 * abs(value_range)
+
+    fig = Figure(figsize=(canvas_width / 100, canvas_height / 100), dpi=100)
+    ax = fig.add_axes([.1, .15, .85, .75])
+    ax.set_ylim(min_value - range_increment, max_value + range_increment)
+
+    xax = range(0, len(values))
+    yax = values
+
+    ax.set_xticks(xax)
+    ax.set_xticklabels([element.date.strftime('%d %b') for element in
+                       result_data['results']], rotation=75)
+    ax.set_title(result_data['benchmark'].name)
+
+    if result_data['relative']:
+        ax.yaxis.set_major_formatter(FormatStrFormatter('%.2f%%'))
+
+    font_sizes = [16, 16]
+    dimensions = [canvas_width, canvas_height]
+
+    for idx, value in enumerate(dimensions):
+        if value < 500:
+            font_sizes[idx] = 8
+        elif value < 1000:
+            font_sizes[idx] = 12
+    
+    if result_data['relative']:
+        font_sizes[0] -= 2
+
+    for item in ax.get_yticklabels():
+        item.set_fontsize(font_sizes[0])
+
+    for item in ax.get_xticklabels():
+        item.set_fontsize(font_sizes[1])
+
+    ax.title.set_fontsize(font_sizes[1] + 4)
+
+    ax.scatter(xax, yax)
+    ax.plot(xax, yax)
+
+    canvas = FigureCanvasAgg(fig)
+    buf = cStringIO.StringIO()
+    canvas.print_png(buf)
+    buf_data = buf.getvalue()
+
+    return buf_data

codespeed/validators.py

@@ -6,7 +6,7 @@ def validate_results_request(data):
     Validates that a result request dictionary has all needed parameters
     and their type is correct.
 
-    Throws ValidationError on error
+    Throws ValidationError on error.
     """
     mandatory_data = [
         'env',
@@ -24,12 +24,23 @@ def validate_results_request(data):
             raise ValidationError('Value for key "' + key +
                                   '" empty in GET request!')
 
-    # Check that 'revs' is the correct format (if it exists)
-    if 'revs' in data:
-        try:
-            rev_value = int(data['revs'])
-        except ValueError:
-            raise ValidationError('Value for key "revs" is not an integer!')
-        if rev_value <= 0:
-            raise ValidationError('Value for key "revs" should be a'
-                                  ' strictly positive integer!', True)
+    integer_data = [
+            'revs',
+            'width',
+            'height'
+    ]
+
+    """
+    Check that the items in integer_data are the correct format,
+    if they exist
+    """
+    for key in integer_data:
+        if key in data:
+            try:
+                rev_value = int(data[key])
+            except ValueError:
+                raise ValidationError('Value for "' + key +
+                                      '" is not an integer!')
+            if rev_value <= 0:
+                raise ValidationError('Value for "' + key + '" should be a'
+                                      ' strictly positive integer!')

codespeed/views.py

@@ -23,12 +23,7 @@
 from .results import save_result, create_report_if_enough_data
 from . import commits
 from .validators import validate_results_request
-
-import cStringIO
-from matplotlib.figure import Figure
-from matplotlib.ticker import FormatStrFormatter
-from matplotlib.backends.backend_agg import FigureCanvasAgg
-
+from .images import gen_image_from_results
 
 logger = logging.getLogger(__name__)
 
@@ -763,65 +758,17 @@ def makeimage(request):
     except ObjectDoesNotExist as err:
         return HttpResponseNotFound(str(err))
 
-    canvas_width = int(data['width']) if 'width' in data else 600
-    canvas_height = int(data['height']) if 'height' in data else 500
-
-    canvas_width = max(canvas_width, 400)
-    canvas_height = max(canvas_height, 300)
-
-    values = [element.value for element in result_data['results']]
-
-    max_value = max(values)
-    min_value = min(values)
-    value_range = max_value - min_value
-    range_increment = 0.05 * abs(value_range)
-
-    fig = Figure(figsize=(canvas_width / 100, canvas_height / 100), dpi=100)
-    ax = fig.add_axes([.1, .15, .85, .75])
-    ax.set_ylim(min_value - range_increment, max_value + range_increment)
-
-    xax = range(0, len(values))
-    yax = values
-
-    ax.set_xticks(xax)
-    ax.set_xticklabels([element.date.strftime('%d %b') for element in
-                       result_data['results']], rotation=75)
-    ax.set_title(result_data['benchmark'].name)
-
-    if result_data['relative']:
-        ax.yaxis.set_major_formatter(FormatStrFormatter('%.3f%%'))
-
-    font_sizes = [16, 16]
-    dimensions = [canvas_width, canvas_height]
-
-    for idx, value in enumerate(dimensions):
-        if value < 500:
-            font_sizes[idx] = 8
-        elif value < 1000:
-            font_sizes[idx] = 12
-
-    for item in ax.get_yticklabels():
-        item.set_fontsize(font_sizes[0])
-
-    for item in ax.get_xticklabels():
-        item.set_fontsize(font_sizes[1])
-
-    ax.title.set_fontsize(font_sizes[1] + 4)
-
-    ax.scatter(xax, yax)
-    ax.plot(xax, yax)
-
-    canvas = FigureCanvasAgg(fig)
-    buf = cStringIO.StringIO()
-    canvas.print_png(buf)
-    buf_data = buf.getvalue()
+    image_data = gen_image_from_results(
+                    result_data,
+                    int(data['width']) if 'width' in data else None,
+                    int(data['height']) if 'height' in data else None)
 
     if django_has_content_type():
-        response = HttpResponse(content=buf_data, content_type='image/png')
+        response = HttpResponse(content=image_data, content_type='image/png')
     else:
-        response = HttpResponse(content=buf_data, mimetype='image/png')
+        response = HttpResponse(content=image_data, mimetype='image/png')
 
-    response['Content-Length'] = len(buf_data)
+    response['Content-Length'] = len(image_data)
     response['Content-Disposition'] = 'attachment; filename=image.png'
 
     return response