1 files changed, 81 insertions, 1 deletions
diff --git a/net/dns/dns_config_service.cc b/net/dns/dns_config_service.cc
index f32f293..ed3f1d2 100644
--- a/net/dns/dns_config_service.cc
+++ b/net/dns/dns_config_service.cc
@@ -4,6 +4,7 @@
 
 #include "net/dns/dns_config_service.h"
 
+#include "base/file_util.h"
 #include "net/base/ip_endpoint.h"
 
 namespace net {
@@ -18,7 +19,7 @@ DnsConfig::DnsConfig()
 
 DnsConfig::~DnsConfig() {}
 
-bool DnsConfig::Equals(const DnsConfig& d) const {
+bool DnsConfig::EqualsIgnoreHosts(const DnsConfig& d) const {
   return (nameservers == d.nameservers) &&
          (search == d.search) &&
          (ndots == d.ndots) &&
@@ -28,5 +29,84 @@ bool DnsConfig::Equals(const DnsConfig& d) const {
          (edns0 == d.edns0);
 }
 
+bool DnsConfig::Equals(const DnsConfig& d) const {
+  return EqualsIgnoreHosts(d) && (hosts == d.hosts);
+}
+
+DnsConfigService::DnsConfigService()
+  : have_config_(false),
+    have_hosts_(false) {}
+
+DnsConfigService::~DnsConfigService() {}
+
+void DnsConfigService::AddObserver(Observer* observer) {
+  DCHECK(CalledOnValidThread());
+  observers_.AddObserver(observer);
+  if (have_config_ && have_hosts_) {
+    observer->OnConfigChanged(dns_config_);
+  }
+}
+
+void DnsConfigService::RemoveObserver(Observer* observer) {
+  DCHECK(CalledOnValidThread());
+  observers_.RemoveObserver(observer);
+}
+
+void DnsConfigService::OnConfigRead(const DnsConfig& config) {
+  DCHECK(CalledOnValidThread());
+  if (!config.EqualsIgnoreHosts(dns_config_)) {
+    DnsConfig copy = config;
+    copy.hosts.swap(dns_config_.hosts);
+    dns_config_ = copy;
+    have_config_ = true;
+    if (have_hosts_) {
+      FOR_EACH_OBSERVER(Observer, observers_, OnConfigChanged(dns_config_));
+    }
+  }
+}
+
+void DnsConfigService::OnHostsRead(const DnsHosts& hosts) {
+  DCHECK(CalledOnValidThread());
+  if (hosts != dns_config_.hosts || !have_hosts_) {
+    dns_config_.hosts = hosts;
+    have_hosts_ = true;
+    if (have_config_) {
+      FOR_EACH_OBSERVER(Observer, observers_, OnConfigChanged(dns_config_));
+    }
+  }
+}
+
+DnsHostsReader::DnsHostsReader(DnsConfigService* service)
+  : service_(service),
+    success_(false) {
+  DCHECK(service);
+}
+
+// Reads the contents of the file at |path| into |str| if the total length is
+// less than |size|.
+static bool ReadFile(const FilePath& path, int64 size, std::string* str) {
+  int64 sz;
+  if (!file_util::GetFileSize(path, &sz) || sz > size)
+    return false;
+  return file_util::ReadFileToString(path, str);
+}
+
+void DnsHostsReader::DoRead() {
+  success_ = false;
+  std::string contents;
+  const int64 kMaxHostsSize = 1 << 16;
+  if (ReadFile(get_path(), kMaxHostsSize, &contents)) {
+    success_ = true;
+    ParseHosts(contents, &dns_hosts_);
+  }
+}
+
+void DnsHostsReader::OnReadFinished() {
+  if (success_)
+    service_->OnHostsRead(dns_hosts_);
+}
+
+DnsHostsReader::~DnsHostsReader() {}
+
 }  // namespace net