From 57b95057311d4dafb948c78889693a98ec349460 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 26 Jul 2017 17:21:46 +0200
Subject: nix search: Add a cache

The package list is now cached in
~/.cache/nix/package-search.json. This gives a substantial speedup to
"nix search" queries. For example (on an SSD):

First run: (no package search cache, cold page cache)

  $ time nix search blender
  Attribute name: nixpkgs.blender
  Package name: blender
  Version: 2.78c
  Description: 3D Creation/Animation/Publishing System

  real    0m6.516s

Second run: (package search cache populated)

  $ time nix search blender
  Attribute name: nixpkgs.blender
  Package name: blender
  Version: 2.78c
  Description: 3D Creation/Animation/Publishing System

  real    0m0.143s
---
 src/libutil/json.cc | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

(limited to 'src/libutil/json.cc')

diff --git a/src/libutil/json.cc b/src/libutil/json.cc
index b8b8ef9c8cca..813b257016e4 100644
--- a/src/libutil/json.cc
+++ b/src/libutil/json.cc
@@ -50,20 +50,22 @@ template<> void toJSON<std::nullptr_t>(std::ostream & str, const std::nullptr_t
 JSONWriter::JSONWriter(std::ostream & str, bool indent)
     : state(new JSONState(str, indent))
 {
-    state->stack.push_back(this);
+    state->stack++;
 }
 
 JSONWriter::JSONWriter(JSONState * state)
     : state(state)
 {
-    state->stack.push_back(this);
+    state->stack++;
 }
 
 JSONWriter::~JSONWriter()
 {
-    assertActive();
-    state->stack.pop_back();
-    if (state->stack.empty()) delete state;
+    if (state) {
+        assertActive();
+        state->stack--;
+        if (state->stack == 0) delete state;
+    }
 }
 
 void JSONWriter::comma()
@@ -121,9 +123,11 @@ void JSONObject::open()
 
 JSONObject::~JSONObject()
 {
-    state->depth--;
-    if (state->indent && !first) indent();
-    state->str << "}";
+    if (state) {
+        state->depth--;
+        if (state->indent && !first) indent();
+        state->str << "}";
+    }
 }
 
 void JSONObject::attr(const std::string & s)
-- 
cgit 1.4.1