// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/site_details.h"

#include "base/metrics/histogram.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/render_frame_host.h"
#include "content/public/browser/render_process_host.h"
#include "url/origin.h"

#if defined(ENABLE_EXTENSIONS)
#include "extensions/browser/extension_registry.h"
#include "extensions/common/constants.h"
#include "extensions/common/extension.h"
#endif

using content::BrowserContext;
using content::BrowserThread;
using content::RenderFrameHost;
using content::RenderProcessHost;
using content::SiteInstance;
using content::WebContents;

namespace {

bool ShouldIsolate(BrowserContext* browser_context,
                   const IsolationScenario* scenario,
                   const GURL& site) {
  switch (scenario->policy) {
    case ISOLATE_NOTHING:
      return false;
    case ISOLATE_ALL_SITES:
      return true;
    case ISOLATE_HTTPS_SITES:
      // Note: For estimation purposes "isolate https sites" is really
      // implemented as "isolate non-http sites". This means that, for example,
      // the New Tab Page gets counted as two processes under this policy, and
      // extensions are isolated as well.
      return !site.SchemeIs(url::kHttpScheme);
    case ISOLATE_EXTENSIONS: {
#if !defined(ENABLE_EXTENSIONS)
      return false;
#else
      if (!site.SchemeIs(extensions::kExtensionScheme))
        return false;
      extensions::ExtensionRegistry* registry =
          extensions::ExtensionRegistry::Get(browser_context);
      const extensions::Extension* extension =
          registry->enabled_extensions().GetExtensionOrAppByURL(site);
      return extension && !extension->is_hosted_app();
#endif
    }
  }
  NOTREACHED();
  return true;
}

// Walk the frame tree and update |scenario|'s data for the given frame. Memoize
// each frame's computed URL in |frame_urls| so it can be reused when visiting
// its children.
void CollectForScenario(std::map<RenderFrameHost*, GURL>* frame_urls,
                        SiteInstance* primary,
                        IsolationScenario* scenario,
                        RenderFrameHost* frame) {
  BrowserContext* context = primary->GetBrowserContext();

  // Determine the site from the frame's origin, with a fallback to the
  // frame's URL.  In cases like <iframe sandbox>, we can wind up with an http
  // URL but a unique origin.  The origin of the resource will still determine
  // process placement.
  url::Origin origin = frame->GetLastCommittedOrigin();
  GURL site = SiteInstance::GetSiteForURL(
      context, origin.unique() ? frame->GetLastCommittedURL()
                               : GURL(origin.Serialize()));

  bool should_isolate = ShouldIsolate(context, scenario, site);

  // Treat a subframe as part of its parent site if neither needs isolation.
  if (!should_isolate && frame->GetParent()) {
    GURL parent_site = (*frame_urls)[frame->GetParent()];
    if (!ShouldIsolate(context, scenario, parent_site))
      site = parent_site;
  }

  bool process_per_site =
      site.is_valid() &&
      RenderProcessHost::ShouldUseProcessPerSite(context, site);

  // If we don't need a dedicated process, and aren't living in a process-
  // per-site process, we are nothing special: collapse our URL to a dummy
  // site.
  if (!process_per_site && !should_isolate)
    site = GURL("http://");

  // We model process-per-site by only inserting those sites into the first
  // browsing instance in which they appear.
  if (scenario->sites.insert(site).second || !process_per_site)
    scenario->browsing_instance_site_map[primary->GetId()].insert(site);

  // Record our result in |frame_urls| for use by children.
  (*frame_urls)[frame] = site;
}

content::SiteInstance* DeterminePrimarySiteInstance(
    content::SiteInstance* instance,
    SiteData* site_data) {
  // Find the BrowsingInstance this WebContents belongs to by iterating over
  // the "primary" SiteInstances of each BrowsingInstance we've seen so far.
  for (auto& existing_site_instance : site_data->instances) {
    if (instance->IsRelatedSiteInstance(existing_site_instance.first)) {
      existing_site_instance.second.insert(instance);
      return existing_site_instance.first;
    }
  }

  // Add |instance| as the "primary" SiteInstance of a new BrowsingInstance.
  site_data->instances[instance].clear();
  site_data->instances[instance].insert(instance);

  return instance;
}

void CollectCurrentSnapshot(SiteData* site_data, RenderFrameHost* frame) {
  if (frame->GetParent()) {
    if (frame->GetSiteInstance() != frame->GetParent()->GetSiteInstance())
      site_data->out_of_process_frames++;
  }

  DeterminePrimarySiteInstance(frame->GetSiteInstance(), site_data);
}

}  // namespace

IsolationScenario::IsolationScenario() : policy(ISOLATE_ALL_SITES) {}

IsolationScenario::~IsolationScenario() {}

SiteData::SiteData() : out_of_process_frames(0) {
  for (int i = 0; i <= ISOLATION_SCENARIO_LAST; i++)
    scenarios[i].policy = static_cast<IsolationScenarioType>(i);
}

SiteData::~SiteData() {}

SiteDetails::SiteDetails() {}

SiteDetails::~SiteDetails() {}

void SiteDetails::CollectSiteInfo(WebContents* contents,
                                  SiteData* site_data) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  SiteInstance* primary =
      DeterminePrimarySiteInstance(contents->GetSiteInstance(), site_data);

  // Now keep track of how many sites we have in this BrowsingInstance (and
  // overall), including sites in iframes.
  for (IsolationScenario& scenario : site_data->scenarios) {
    std::map<RenderFrameHost*, GURL> memo;
    contents->ForEachFrame(
        base::Bind(&CollectForScenario, base::Unretained(&memo),
                   base::Unretained(primary), base::Unretained(&scenario)));
  }

  contents->ForEachFrame(
      base::Bind(&CollectCurrentSnapshot, base::Unretained(site_data)));
}

void SiteDetails::UpdateHistograms(
    const BrowserContextSiteDataMap& site_data_map,
    int all_renderer_process_count,
    int non_renderer_process_count) {
  // Reports a set of site-based process metrics to UMA.
  int process_limit = RenderProcessHost::GetMaxRendererProcessCount();

  // Sum the number of sites and SiteInstances in each BrowserContext and
  // the total number of out-of-process iframes.
  int num_sites[ISOLATION_SCENARIO_LAST + 1] = {};
  int num_isolated_site_instances[ISOLATION_SCENARIO_LAST + 1] = {};
  int num_browsing_instances = 0;
  int num_oopifs = 0;
  for (BrowserContextSiteDataMap::const_iterator i = site_data_map.begin();
       i != site_data_map.end(); ++i) {
    for (const IsolationScenario& scenario : i->second.scenarios) {
      num_sites[scenario.policy] += scenario.sites.size();
      for (auto& browsing_instance : scenario.browsing_instance_site_map) {
        num_isolated_site_instances[scenario.policy] +=
            browsing_instance.second.size();
      }
    }
    num_browsing_instances += i->second.scenarios[ISOLATE_ALL_SITES]
                                  .browsing_instance_site_map.size();
    for (const auto& site_instance : i->second.instances) {
      UMA_HISTOGRAM_COUNTS_100("SiteIsolation.SiteInstancesPerBrowsingInstance",
                               site_instance.second.size());
    }
    num_oopifs += i->second.out_of_process_frames;
  }

  // Predict the number of processes needed when isolating all sites, when
  // isolating only HTTPS sites, and when isolating extensions.
  int process_count_lower_bound[ISOLATION_SCENARIO_LAST + 1];
  int process_count_upper_bound[ISOLATION_SCENARIO_LAST + 1];
  int process_count_estimate[ISOLATION_SCENARIO_LAST + 1];
  for (int policy = 0; policy <= ISOLATION_SCENARIO_LAST; policy++) {
    process_count_lower_bound[policy] = num_sites[policy];
    process_count_upper_bound[policy] = num_sites[policy] + process_limit - 1;
    process_count_estimate[policy] = std::min(
        num_isolated_site_instances[policy], process_count_upper_bound[policy]);
  }

  // Just renderer process count:
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.CurrentRendererProcessCount",
                           all_renderer_process_count);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.BrowsingInstanceCount",
      num_browsing_instances);
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.OutOfProcessIframes", num_oopifs);

  // ISOLATE_NOTHING metrics.
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.IsolateNothingProcessCountNoLimit",
                           num_isolated_site_instances[ISOLATE_NOTHING]);
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.IsolateNothingProcessCountLowerBound",
                           process_count_lower_bound[ISOLATE_NOTHING]);
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.IsolateNothingProcessCountEstimate",
                           process_count_estimate[ISOLATE_NOTHING]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateNothingTotalProcessCountEstimate",
      process_count_estimate[ISOLATE_NOTHING] + non_renderer_process_count);

  // ISOLATE_ALL_SITES metrics.
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.IsolateAllSitesProcessCountNoLimit",
                           num_isolated_site_instances[ISOLATE_ALL_SITES]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateAllSitesProcessCountLowerBound",
      process_count_lower_bound[ISOLATE_ALL_SITES]);
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.IsolateAllSitesProcessCountEstimate",
                           process_count_estimate[ISOLATE_ALL_SITES]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateAllSitesTotalProcessCountEstimate",
      process_count_estimate[ISOLATE_ALL_SITES] + non_renderer_process_count);

  // ISOLATE_HTTPS_SITES metrics.
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.IsolateHttpsSitesProcessCountNoLimit",
                           num_isolated_site_instances[ISOLATE_HTTPS_SITES]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateHttpsSitesProcessCountLowerBound",
      process_count_lower_bound[ISOLATE_HTTPS_SITES]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateHttpsSitesProcessCountEstimate",
      process_count_estimate[ISOLATE_HTTPS_SITES]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateHttpsSitesTotalProcessCountEstimate",
      process_count_estimate[ISOLATE_HTTPS_SITES] + non_renderer_process_count);

  // ISOLATE_EXTENSIONS metrics.
  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.IsolateExtensionsProcessCountNoLimit",
                           num_isolated_site_instances[ISOLATE_EXTENSIONS]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateExtensionsProcessCountLowerBound",
      process_count_lower_bound[ISOLATE_EXTENSIONS]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateExtensionsProcessCountEstimate",
      process_count_estimate[ISOLATE_EXTENSIONS]);
  UMA_HISTOGRAM_COUNTS_100(
      "SiteIsolation.IsolateExtensionsTotalProcessCountEstimate",
      process_count_estimate[ISOLATE_EXTENSIONS] + non_renderer_process_count);
}