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/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ex: set tabstop=8 softtabstop=2 shiftwidth=2 expandtab: */
/* 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 nsCUPSShim_h___
#define nsCUPSShim_h___
#include <cups/cups.h>
#include "mozilla/Atomics.h"
#include "mozilla/Mutex.h"
// TODO: This should be a configure option, ideally.
#ifndef XP_MACOSX
# define CUPS_SHIM_RUNTIME_LINK
#endif
struct PRLibrary;
/* Note: this class relies on static initialization. */
class nsCUPSShim {
public:
bool EnsureInitialized() { return mInited || Init(); }
/**
* Function pointers for supported functions. These are only
* valid after successful initialization.
*/
#define CUPS_SHIM_ALL_FUNCS(X) \
X(cupsAddOption) \
X(cupsCheckDestSupported) \
X(cupsConnectDest) \
X(cupsCopyDest) \
X(cupsCopyDestInfo) \
X(cupsDoRequest) \
X(cupsFreeDestInfo) \
X(cupsFreeDests) \
X(cupsGetDestMediaDefault) \
X(cupsGetDestMediaCount) \
X(cupsGetDestMediaByIndex) \
X(cupsGetDest) \
X(cupsGetDests) \
X(cupsGetNamedDest) \
X(cupsGetOption) \
X(cupsLocalizeDestMedia) \
X(cupsPrintFile) \
X(cupsTempFd) \
X(httpClose) \
X(ippAddString) \
X(ippAddStrings) \
X(ippDelete) \
X(ippFindAttribute) \
X(ippGetCount) \
X(ippGetString) \
X(ippNewRequest)
#ifdef CUPS_SHIM_RUNTIME_LINK
// Define a single field which holds a function pointer.
# define CUPS_SHIM_FUNC_DECL(X) decltype(::X)* X;
#else
// Define a static constexpr function pointer. GCC can sometimes optimize
// away the pointer fetch for this.
# define CUPS_SHIM_FUNC_DECL(X) static constexpr decltype(::X)* const X = ::X;
#endif
CUPS_SHIM_ALL_FUNCS(CUPS_SHIM_FUNC_DECL)
#undef CUPS_SHIM_FUNC_DECL
private:
/**
* Initialize this object. Attempt to load the CUPS shared
* library and find function pointers for the supported
* functions (see below).
* @return false if the shared library could not be loaded, or if
* any of the functions could not be found.
* true for successful initialization.
*/
bool Init();
// We can try to get initialized from multiple threads at the same time, this
// boolean and the mutex below make it safe.
//
// The boolean can't be Relaxed, because it guards our function pointers.
mozilla::Atomic<bool, mozilla::ReleaseAcquire> mInited{false};
#ifdef CUPS_SHIM_RUNTIME_LINK
mozilla::OffTheBooksMutex mInitMutex{"nsCUPSShim::mInitMutex"};
PRLibrary* mCupsLib;
#endif
};
#endif /* nsCUPSShim_h___ */