Function graph_diff

Source

pub fn graph_diff(
    graph1: &SqliteGraph,
    graph2: &SqliteGraph,
) -> Result<GraphDiffResult, SqliteGraphError>

Expand description

Computes structural graph diff between two snapshots.

Returns comprehensive delta information including nodes/edges added/removed and similarity metrics from Phase 54’s structural_similarity() function.

§Arguments

graph1 - First graph (baseline, “before” snapshot)
graph2 - Second graph (comparison, “after” snapshot)

§Returns

GraphDiffResult containing:

nodes_added: Nodes present in graph2 but not in graph1
nodes_removed: Nodes present in graph1 but not in graph2
edges_added: Edges present in graph2 but not in graph1
edges_removed: Edges present in graph1 but not in graph2
similarity_score: Structural similarity (0.0 to 1.0)
is_isomorphic: True if graphs are structurally identical
graph_edit_distance: Simplified GED (1.0 - similarity)
graph1_size: Number of nodes in graph1
graph2_size: Number of nodes in graph2

§Example

use sqlitegraph::{algo::graph_diff, SqliteGraph};

let graph_v1 = SqliteGraph::open_in_memory()?;
let graph_v2 = SqliteGraph::open_in_memory()?;
// ... build graphs representing different versions ...

let diff = graph_diff(&graph_v1, &graph_v2)?;

if diff.has_breaking_changes() {
    println!("WARNING: {} nodes removed", diff.nodes_removed.len());
} else if diff.is_safe() {
    println!("Refactor looks safe (similarity: {:.2})", diff.similarity_score);
}

// See detailed changes
for &node_id in &diff.nodes_added {
    println!("Added node: {}", node_id);
}

§Use Cases

Regression Detection: Compare test runs to identify what changed
Refactor Validation: Verify optimization preserved structure
Version Comparison: Track structural evolution across versions
Impact Analysis: Identify affected regions by diffing before/after

§Complexity

Time: O(V + E) for delta computation + isomorphism check time Space: O(V + E) for storing delta sets

graph_diff