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heapgraph_stats

Note

This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information.

General statistics on the heap graph

namespace HH;

function heapgraph_stats(
  resource $heapgraph,
): darray<string, int>;

Parameters​

  • resource $heapgraph - The resource obtained with heapgraph_create

Returns​

  • array<string, - int> - General metrics describing the heap graph. Keys are defined as follows:

nodes count of nodes in the graph edges count of pointers (edges) in the graph roots count of root->nonroot pointers (pointers where from is root) root_nodes count of root nodes exact 1 if type scanners were built, 0 otherwise