Allow to drill down into multiple generations

README.md

@@ -123,14 +123,20 @@ $ heapy read tmp/2015-10-01T10:18:59-05:00-heap.dump 17 --lines=6
 
 > Note: Default lines value is 50
 
-### Reviewing all generations
+### Reviewing multiple generations
 
 If you want to read all generations you can use the "all" directive
 
 ```
 $ heapy read tmp/2015-10-01T10:18:59-05:00-heap.dump all
 ```
 
+Alternatively you can provide a range of generations that should be considered
+
+```
+$ heapy read tmp/2015-10-01T10:18:59-05:00-heap.dump 5-10
+```
+
 You can also use T-Lo's online JS based [Heap Analyzer](http://tenderlove.github.io/heap-analyzer/) for visualizations. Another tool is [HARB](https://github.com/csfrancis/harb)
 
 ## Development

lib/heapy/analyzer.rb

@@ -27,13 +27,19 @@ def read
       end
     end
 
-    def drill_down(generation_to_inspect, max_items_to_display)
+    def drill_down(generations_to_inspect, max_items_to_display)
       puts ""
-      puts "Analyzing Heap (Generation: #{generation_to_inspect})"
+      puts "Analyzing Heap (Generation: #{generations_to_inspect})"
       puts "-------------------------------"
       puts ""
 
-      generation_to_inspect = Integer(generation_to_inspect) unless generation_to_inspect == "all"
+      min_gen, max_gen = if generations_to_inspect == "all"
+                           [nil, nil]
+                         else
+                           generations_to_inspect.split("-").map { |gen| Integer(gen) }
+                         end
+
+      max_gen = min_gen if min_gen && !max_gen # single generation selected
 
       memsize_hash    = counters_hash
       count_hash      = counters_hash
@@ -49,7 +55,7 @@ def drill_down(generation_to_inspect, max_items_to_display)
         end
 
         generation = parsed["generation"] || 0
-        if generation_to_inspect == "all".freeze || generation == generation_to_inspect
+        if min_gen.nil? || (generation >= min_gen && generation <= max_gen)
           next unless parsed["file"]
 
           key = "#{ parsed["file"] }:#{ parsed["line"] }"
@@ -70,7 +76,7 @@ def drill_down(generation_to_inspect, max_items_to_display)
         end
       end
 
-      raise "not a valid Generation: #{generation_to_inspect.inspect}" if memsize_hash.empty?
+      raise "Nothing found in generation: #{generations_to_inspect.inspect}" if memsize_hash.empty?
 
       total_memsize = memsize_hash.inject(0){|count, (k, v)| count += v}
 

spec/heap_inspect_spec.rb

@@ -36,6 +36,15 @@
     expect(out).to match("19046  String")
   end
 
+  it "drills down some" do
+    out = run("bin/heapy read #{ fixtures('dumps/00-heap.dump') } 35-36")
+    # memory count
+    expect(out).to match("377065  /Users/richardschneeman/Documents/projects/codetriage/app/views/layouts/application.html.slim:1")
+
+    # class counts
+    expect(out).to match("8220  String")
+  end
+
   it "drills down" do
     out = run("bin/heapy read #{ fixtures('dumps/00-heap.dump') } 36")