Class: HeapScope::Snapshot

Inherits:
Object
  • Object
show all
Defined in:
lib/heapscope/snapshot.rb

Overview

Stable snapshot abstraction. Configurable fidelity — not a full heap dump.

Constant Summary collapse

SCHEMA_VERSION = 
HeapScope::SCHEMA_VERSION
SLIM_CLASS_LIMIT = 
40
SLIM_ALLOC_LIMIT = 
20

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(id:, timestamp:, mode:, gc_stat:, rss_bytes:, class_stats:, allocation_sites: {}, metadata: {}, limitations: [], sampled: false, process: {}, duration_ms: 0, object_sample: []) ⇒ Snapshot

Returns a new instance of Snapshot.



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# File 'lib/heapscope/snapshot.rb', line 18

def initialize(id:, timestamp:, mode:, gc_stat:, rss_bytes:, class_stats:,
               allocation_sites: {}, metadata: {}, limitations: [],
               sampled: false, process: {}, duration_ms: 0, object_sample: [])
  @id = id
  @timestamp = timestamp
  @mode = mode
  @gc_stat = gc_stat || {}
  @rss_bytes = rss_bytes
  @class_stats = class_stats || {}
  @allocation_sites = allocation_sites || {}
  @metadata = metadata || {}
  @limitations = limitations || []
  @sampled = sampled
  @process = process || {}
  @duration_ms = duration_ms
  @object_sample = object_sample || []
end

Instance Attribute Details

#allocation_sites ⇒ Object (readonly)

Returns the value of attribute allocation_sites.



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# File 'lib/heapscope/snapshot.rb', line 14

def allocation_sites
  @allocation_sites
end

#class_stats ⇒ Object (readonly)

Returns the value of attribute class_stats.



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# File 'lib/heapscope/snapshot.rb', line 14

def class_stats
  @class_stats
end

#duration_ms ⇒ Object (readonly)

Returns the value of attribute duration_ms.



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# File 'lib/heapscope/snapshot.rb', line 14

def duration_ms
  @duration_ms
end

#gc_stat ⇒ Object (readonly)

Returns the value of attribute gc_stat.



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# File 'lib/heapscope/snapshot.rb', line 14

def gc_stat
  @gc_stat
end

#id ⇒ Object (readonly)

Returns the value of attribute id.



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# File 'lib/heapscope/snapshot.rb', line 14

def id
  @id
end

#limitations ⇒ Object (readonly)

Returns the value of attribute limitations.



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# File 'lib/heapscope/snapshot.rb', line 14

def limitations
  @limitations
end

#metadata ⇒ Object (readonly)

Returns the value of attribute metadata.



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# File 'lib/heapscope/snapshot.rb', line 14

def metadata
  @metadata
end

#mode ⇒ Object (readonly)

Returns the value of attribute mode.



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# File 'lib/heapscope/snapshot.rb', line 14

def mode
  @mode
end

#object_sample ⇒ Object (readonly)

Returns the value of attribute object_sample.



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# File 'lib/heapscope/snapshot.rb', line 14

def object_sample
  @object_sample
end

#process ⇒ Object (readonly)

Returns the value of attribute process.



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# File 'lib/heapscope/snapshot.rb', line 14

def process
  @process
end

#rss_bytes ⇒ Object (readonly)

Returns the value of attribute rss_bytes.



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# File 'lib/heapscope/snapshot.rb', line 14

def rss_bytes
  @rss_bytes
end

#sampled ⇒ Object (readonly)

Returns the value of attribute sampled.



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# File 'lib/heapscope/snapshot.rb', line 14

def sampled
  @sampled
end

#timestamp ⇒ Object (readonly)

Returns the value of attribute timestamp.



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# File 'lib/heapscope/snapshot.rb', line 14

def timestamp
  @timestamp
end

Class Method Details

.from_h(data) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 126

def self.from_h(data)
  class_stats = (data[:class_stats] || {}).each_with_object({}) do |(name, stats), hash|
    hash[name.to_s] = {
      name: name.to_s,
      count: stats[:count].to_i,
      shallow_bytes: stats[:shallow_bytes].to_i,
      average_bytes: stats[:average_bytes].to_f
    }
  end

  new(
    id: data[:id] || SecureRandom.hex(8),
    timestamp: Time.parse(data[:timestamp].to_s),
    mode: (data[:mode] || "standard").to_sym,
    gc_stat: symbolize_keys(data[:gc_stat] || {}),
    rss_bytes: data[:rss_bytes],
    class_stats: class_stats,
    allocation_sites: data[:allocation_sites] || {},
    metadata: data[:metadata] || {},
    limitations: data[:limitations] || [],
    sampled: data[:sampled] || false,
    process: data[:process] || {},
    duration_ms: data[:duration_ms].to_f,
    object_sample: data[:object_sample] || []
  )
end

.load(path) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 121

def self.load(path)
  data = JSON.parse(File.read(path), symbolize_names: true)
  from_h(data)
end

.stringify_keys(hash) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 153

def self.stringify_keys(hash)
  hash.each_with_object({}) { |(k, v), h| h[k.to_s] = v }
end

.symbolize_keys(hash) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 157

def self.symbolize_keys(hash)
  hash.each_with_object({}) { |(k, v), h| h[k.to_sym] = v }
end

Instance Method Details

#class_bytes(name) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 60

def class_bytes(name)
  (class_stats[name.to_s] || {})[:shallow_bytes].to_i
end

#class_count(name) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 56

def class_count(name)
  (class_stats[name.to_s] || {})[:count].to_i
end

#gc_generation ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 36

def gc_generation
  gc_stat[:count]
end

#heap_free_slots ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 44

def heap_free_slots
  gc_stat[:heap_free_slots]
end

#heap_live_slots ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 40

def heap_live_slots
  gc_stat[:heap_live_slots]
end

#same_process?(other) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/heapscope/snapshot.rb', line 68

def same_process?(other)
  process[:pid] == other.process[:pid]
end

#save(path, slim: false) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 116

def save(path, slim: false)
  File.write(path, JSON.pretty_generate(to_h(slim: slim)))
  path
end

#stringify_keys(hash) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 161

def stringify_keys(hash)
  self.class.stringify_keys(hash)
end

#to_h(slim: false) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 72

def to_h(slim: false)
  stats = class_stats
  sites = allocation_sites
  sample = object_sample
  meta = metadata.dup
  limits = limitations.dup

  if slim
    top = top_classes(SLIM_CLASS_LIMIT)
    stats = top.to_h { |row| [row[:name], row] }
    sites =
      if allocation_sites.is_a?(Hash)
        allocation_sites.to_a.first(SLIM_ALLOC_LIMIT).to_h
      else
        Array(allocation_sites).first(SLIM_ALLOC_LIMIT)
      end
    sample = []
    meta[:slim] = true
    limits << "slim_json_truncated_classes" unless limits.include?("slim_json_truncated_classes")
  end

  {
    schema_version: SCHEMA_VERSION,
    heapscope_version: VERSION,
    id: id,
    timestamp: timestamp.iso8601(3),
    mode: mode.to_s,
    gc_stat: stringify_keys(gc_stat),
    rss_bytes: rss_bytes,
    class_stats: stats.transform_values { |v| stringify_keys(v) },
    allocation_sites: sites,
    metadata: meta,
    limitations: limits,
    sampled: sampled,
    process: process,
    duration_ms: duration_ms,
    object_sample: sample
  }
end

#to_json(*_args) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 112

def to_json(*_args)
  JSON.pretty_generate(to_h)
end

#top_classes(limit = 20, by: :count) ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 64

def top_classes(limit = 20, by: :count)
  class_stats.values.sort_by { |s| -(s[by] || 0) }.first(limit)
end

#total_allocated_objects ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 48

def total_allocated_objects
  gc_stat[:total_allocated_objects]
end

#total_freed_objects ⇒ Object 



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# File 'lib/heapscope/snapshot.rb', line 52

def total_freed_objects
  gc_stat[:total_freed_objects]
end