gecko-dev/netwerk/protocol/http/nsHttpResponseHead.h

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsHttpResponseHead_h__
#define nsHttpResponseHead_h__

#include "nsHttpHeaderArray.h"
#include "nsHttp.h"
#include "nsString.h"
#include "mozilla/RecursiveMutex.h"

class nsIHttpHeaderVisitor;

// This needs to be forward declared here so we can include only this header
// without also including PHttpChannelParams.h
namespace IPC {
template <typename>
struct ParamTraits;
}  // namespace IPC

namespace mozilla {
namespace net {

//-----------------------------------------------------------------------------
// nsHttpResponseHead represents the status line and headers from an HTTP
// response.
//-----------------------------------------------------------------------------

class nsHttpResponseHead {
 public:
  nsHttpResponseHead()
      : mVersion(HttpVersion::v1_1),
        mStatus(200),
        mContentLength(-1),
        mCacheControlPrivate(false),
        mCacheControlNoStore(false),
        mCacheControlNoCache(false),
        mCacheControlImmutable(false),
        mPragmaNoCache(false),
        mRecursiveMutex("nsHttpResponseHead.mRecursiveMutex"),
        mInVisitHeaders(false) {}

  nsHttpResponseHead(const nsHttpResponseHead &aOther);
  nsHttpResponseHead &operator=(const nsHttpResponseHead &aOther);

  void Enter() { mRecursiveMutex.Lock(); }
  void Exit() { mRecursiveMutex.Unlock(); }

  HttpVersion Version();
// X11's Xlib.h #defines 'Status' to 'int' on some systems!
#undef Status
  uint16_t Status();
  void StatusText(nsACString &aStatusText);
  int64_t ContentLength();
  void ContentType(nsACString &aContentType);
  void ContentCharset(nsACString &aContentCharset);
  bool Private();
  bool NoStore();
  bool NoCache();
  bool Immutable();
  /**
   * Full length of the entity. For byte-range requests, this may be larger
   * than ContentLength(), which will only represent the requested part of the
   * entity.
   */
  int64_t TotalEntitySize();

  MOZ_MUST_USE nsresult SetHeader(const nsACString &h, const nsACString &v,
                                  bool m = false);
  MOZ_MUST_USE nsresult SetHeader(nsHttpAtom h, const nsACString &v,
                                  bool m = false);
  MOZ_MUST_USE nsresult GetHeader(nsHttpAtom h, nsACString &v);
  void ClearHeader(nsHttpAtom h);
  void ClearHeaders();
  bool HasHeaderValue(nsHttpAtom h, const char *v);
  bool HasHeader(nsHttpAtom h);

  void SetContentType(const nsACString &s);
  void SetContentCharset(const nsACString &s);
  void SetContentLength(int64_t);

  // write out the response status line and headers as a single text block,
  // optionally pruning out transient headers (ie. headers that only make
  // sense the first time the response is handled).
  // Both functions append to the string supplied string.
  void Flatten(nsACString &, bool pruneTransients);
  void FlattenNetworkOriginalHeaders(nsACString &buf);

  // The next 2 functions parse flattened response head and original net
  // headers. They are used when we are reading an entry from the cache.
  //
  // To keep proper order of the original headers we MUST call
  // ParseCachedOriginalHeaders FIRST and then ParseCachedHead.
  //
  // block must be null terminated.
  MOZ_MUST_USE nsresult ParseCachedHead(const char *block);
  MOZ_MUST_USE nsresult ParseCachedOriginalHeaders(char *block);

  // parse the status line.
  void ParseStatusLine(const nsACString &line);

  // parse a header line.
  MOZ_MUST_USE nsresult ParseHeaderLine(const nsACString &line);

  // cache validation support methods
  MOZ_MUST_USE nsresult ComputeFreshnessLifetime(uint32_t *);
  MOZ_MUST_USE nsresult ComputeCurrentAge(uint32_t now, uint32_t requestTime,
                                          uint32_t *result);
  bool MustValidate();
  bool MustValidateIfExpired();

  // returns true if the server appears to support byte range requests.
  bool IsResumable();

  // returns true if the Expires header has a value in the past relative to the
  // value of the Date header.
  bool ExpiresInPast();

  // update headers...
  MOZ_MUST_USE nsresult UpdateHeaders(nsHttpResponseHead *headers);

  // reset the response head to it's initial state
  void Reset();

  MOZ_MUST_USE nsresult GetAgeValue(uint32_t *result);
  MOZ_MUST_USE nsresult GetMaxAgeValue(uint32_t *result);
  MOZ_MUST_USE nsresult GetDateValue(uint32_t *result);
  MOZ_MUST_USE nsresult GetExpiresValue(uint32_t *result);
  MOZ_MUST_USE nsresult GetLastModifiedValue(uint32_t *result);

  bool operator==(const nsHttpResponseHead &aOther) const;

  // Using this function it is possible to itereate through all headers
  // automatically under one lock.
  MOZ_MUST_USE nsresult VisitHeaders(nsIHttpHeaderVisitor *visitor,
                                     nsHttpHeaderArray::VisitorFilter filter);
  MOZ_MUST_USE nsresult GetOriginalHeader(nsHttpAtom aHeader,
                                          nsIHttpHeaderVisitor *aVisitor);

  bool HasContentType();
  bool HasContentCharset();

 private:
  MOZ_MUST_USE nsresult SetHeader_locked(nsHttpAtom atom, const nsACString &h,
                                         const nsACString &v, bool m = false);
  void AssignDefaultStatusText();
  void ParseVersion(const char *);
  void ParseCacheControl(const char *);
  void ParsePragma(const char *);

  void ParseStatusLine_locked(const nsACString &line);
  MOZ_MUST_USE nsresult ParseHeaderLine_locked(const nsACString &line,
                                               bool originalFromNetHeaders);

  // these return failure if the header does not exist.
  MOZ_MUST_USE nsresult ParseDateHeader(nsHttpAtom header,
                                        uint32_t *result) const;

  bool ExpiresInPast_locked() const;
  MOZ_MUST_USE nsresult GetAgeValue_locked(uint32_t *result) const;
  MOZ_MUST_USE nsresult GetExpiresValue_locked(uint32_t *result) const;
  MOZ_MUST_USE nsresult GetMaxAgeValue_locked(uint32_t *result) const;

  MOZ_MUST_USE nsresult GetDateValue_locked(uint32_t *result) const {
    return ParseDateHeader(nsHttp::Date, result);
  }

  MOZ_MUST_USE nsresult GetLastModifiedValue_locked(uint32_t *result) const {
    return ParseDateHeader(nsHttp::Last_Modified, result);
  }

 private:
  // All members must be copy-constructable and assignable
  nsHttpHeaderArray mHeaders;
  HttpVersion mVersion;
  uint16_t mStatus;
  nsCString mStatusText;
  int64_t mContentLength;
  nsCString mContentType;
  nsCString mContentCharset;
  bool mCacheControlPrivate;
  bool mCacheControlNoStore;
  bool mCacheControlNoCache;
  bool mCacheControlImmutable;
  bool mPragmaNoCache;

  // We are using RecursiveMutex instead of a Mutex because VisitHeader
  // function calls nsIHttpHeaderVisitor::VisitHeader while under lock.
  RecursiveMutex mRecursiveMutex;
  // During VisitHeader we sould not allow cal to SetHeader.
  bool mInVisitHeaders;

  friend struct IPC::ParamTraits<nsHttpResponseHead>;
};

}  // namespace net
}  // namespace mozilla

#endif  // nsHttpResponseHead_h__