Add JSON output capabilities

Cargo.toml

@@ -12,3 +12,6 @@ cargo = "0.20"
 env_logger = "0.4"
 petgraph = "0.4"
 rustc-serialize = "0.3"
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "1.0"

src/main.rs

@@ -2,6 +2,9 @@ extern crate cargo;
 extern crate env_logger;
 extern crate petgraph;
 extern crate rustc_serialize;
+extern crate serde;
+#[macro_use] extern crate serde_derive;
+extern crate serde_json;
 
 use cargo::{Config, CliResult};
 use cargo::core::{PackageId, Package, Resolve, Workspace};
@@ -16,7 +19,7 @@ use cargo::util::{self, important_paths, CargoResult, Cfg, CargoError};
 use petgraph::EdgeDirection;
 use petgraph::graph::NodeIndex;
 use petgraph::visit::EdgeRef;
-use std::collections::{HashSet, HashMap};
+use std::collections::{HashSet, HashMap, BTreeMap};
 use std::collections::hash_map::Entry;
 use std::env;
 use std::str::{self, FromStr};
@@ -50,6 +53,7 @@ Options:
  --charset CHARSET Set the character set to use in output. Valid
  values: utf8, ascii [default: utf8]
  -f, --format FORMAT Format string for printing dependencies
+ -j, --json Print a JSON representation of the tree
  --manifest-path PATH Path to the manifest to analyze
  -v, --verbose Use verbose output
  -q, --quiet No output printed to stdout other than the tree
@@ -71,6 +75,7 @@ struct Flags {
  flag_no_indent: bool,
  flag_all: bool,
  flag_charset: Charset,
+ flag_json: bool,
  flag_format: Option<String>,
  flag_manifest_path: Option<String>,
  flag_verbose: u32,
@@ -214,6 +219,14 @@ fn real_main(flags: Flags, config: &Config) -> CliResult {
  flags.flag_all);
  println!("");
  }
+ } else if flags.flag_json {
+ println!("{}", serde_json::to_string_pretty(
+ &graph_to_tree(package.package_id(),
+ &packages,
+ &resolve,
+ kind,
+ &graph,
+ direction)?).expect("serialization failed"))
  } else {
  print_tree(root,
  kind,
@@ -317,6 +330,13 @@ struct Graph<'a> {
  nodes: HashMap<&'a PackageId, NodeIndex>,
 }
 
+#[derive(Debug, Serialize, Deserialize)]
+struct Tree {
+ version: String,
+ features: Vec<String>,
+ dependencies: BTreeMap<String, Box<Tree>>,
+}
+
 fn build_graph<'a>(resolve: &'a Resolve,
  packages: &'a PackageSet,
  root: &'a PackageId,
@@ -368,6 +388,57 @@ fn build_graph<'a>(resolve: &'a Resolve,
  Ok(graph)
 }
 
+fn graph_to_tree<'a>(package_id: &'a PackageId,
+ packages: &'a PackageSet,
+ resolve: &'a Resolve,
+ kind: Kind,
+ graph: &Graph<'a>,
+ direction: EdgeDirection) -> CargoResult<Tree> {
+ let mut visited_deps = HashSet::new();
+ graph_to_tree_(package_id,
+ packages,
+ resolve,
+ kind,
+ graph,
+ direction,
+ &mut visited_deps)
+}
+
+fn graph_to_tree_<'a>(package_id: &'a PackageId,
+ packages: &'a PackageSet,
+ resolve: &'a Resolve,
+ kind: Kind,
+ graph: &Graph<'a>,
+ direction: EdgeDirection,
+ visited_deps: &mut HashSet<&'a PackageId>)
+ -> CargoResult<Tree> {
+ let deps = graph.graph
+ .edges_directed(graph.nodes[package_id], direction)
+ .filter(|edge| edge.weight() == &kind)
+ .map(|edge| {
+ match direction {
+ EdgeDirection::Incoming => &graph.graph[edge.source()],
+ EdgeDirection::Outgoing => &graph.graph[edge.target()],
+ }
+ });
+
+ let mut deps_ = BTreeMap::new();
+ for dep in deps {
+ let name = packages.get(dep.id)?.name().to_owned();
+ deps_.insert(name, Box::new(graph_to_tree_(
+ dep.id, packages, resolve, kind, graph, direction, visited_deps)?));
+ }
+
+ let package = packages.get(package_id)?;
+
+ Ok(Tree {
+ version: package.version().to_string(),
+ features: resolve.features_sorted(package_id)
+ .into_iter().map(|x| x.to_owned()).collect(),
+ dependencies: deps_,
+ })
+}
+
 fn print_tree<'a>(package: &'a PackageId,
  kind: Kind,
  graph: &Graph<'a>,