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e8e1f6902e
This XPCOM interface was being initialized and used, and was unnecessary. This patch removes it completely to simplify things, initializing viaduct during xpcom startup instead. This is done rather than keeping it lazy and tied to FOG startup, as the implementation just sets a static atomic to a function pointer. This makes no changes to anything which actually uses viaduct, which is done through the previously mentioned static atomic. Differential Revision: https://phabricator.services.mozilla.com/D162010
47 lines
1.8 KiB
C++
47 lines
1.8 KiB
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
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#ifndef mozilla_Viaduct_h
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#define mozilla_Viaduct_h
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/**
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* Viaduct is a way for Application Services Rust components
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* (https://github.com/mozilla/application-services) to make network requests
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* using a trusted stack (gecko).
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*
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* The way it works is roughly as follows:
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* - First we register a callback using `viaduct_initialize`
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* (InitializeViaduct). This callback is stored on the Rust side
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* in a static variable, therefore InitializeViaduct() must be called only once.
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*
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* - When the Rust code needs to make a network request, our callback
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* (ViaductCallback) will be called with a protocol buffer describing
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* the request to make on their behalf. Note 1: The callback MUST be called from
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* a background thread as it is blocking. Note 2: It is our side responsibility
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* to call `viaduct_destroy_bytebuffer` on the buffer.
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*
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* - We set a semaphore to make the background thread wait while we make the
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* request on the main thread using nsIChannel. (ViaductRequest::MakeRequest)
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*
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* - Once a response is received, we allocate a bytebuffer to store the
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* response using `viaduct_alloc_bytebuffer` and unlock the semaphore.
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* (ViaductRequest::OnStopRequest)
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*
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* - The background thread is unlocked, and the callback returns the response to
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* the Rust caller. (ViaductCallback)
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*
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* - The Rust caller will free the response buffer we allocated earlier.
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*
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* Reference:
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* https://github.com/mozilla/application-services/blob/master/components/viaduct/README.md
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*/
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namespace mozilla {
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// Should only be called once during startup to initialize the Viaduct callback.
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void InitializeViaduct();
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} // namespace mozilla
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#endif // mozilla_Viaduct_h
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