8.9

1 files changed, 268 insertions, 433 deletions

diff --git a/wx+/http.cpp b/wx+/http.cpp
index 3428546e..851b3ed0 100644..100755
--- a/wx+/http.cpp
+++ b/wx+/http.cpp
@@ -1,433 +1,268 @@
-// *****************************************************************************
-// * This file is part of the FreeFileSync project. It is distributed under    *
-// * GNU General Public License: http://www.gnu.org/licenses/gpl-3.0           *
-// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
-// *****************************************************************************
-
-#include "http.h"
-#ifdef ZEN_WIN
-    #include <zen/win.h> //tame WinINet.h include
-    #include <WinINet.h>
-#endif
-
-#if defined ZEN_LINUX || defined ZEN_MAC
-    #include <wx/app.h>
-    #include <zen/thread.h> //std::thread::id
-    #include <wx/protocol/http.h>
-#endif
-
-using namespace zen;
-
-
-namespace
-{
-#ifdef ZEN_WIN
-    #if defined NDEBUG && defined __WXWINDOWS__
-        #error don not use wxWidgets for this component!
-    #endif
-#else
-    #ifndef NDEBUG
-        const std::thread::id mainThreadId = std::this_thread::get_id();
-    #endif
-#endif
-
-struct UrlRedirectError
-{
-    UrlRedirectError(const std::wstring& url) : newUrl(url) {}
-    std::wstring newUrl;
-};
-}
-
-
-class HttpInputStream::Impl
-{
-public:
-    Impl(const std::wstring& url, const std::wstring& userAgent, //throw SysError, UrlRedirectError
-         const std::string* postParams) //issue POST if bound, GET otherwise
-    {
-        ZEN_ON_SCOPE_FAIL( cleanup(); /*destructor call would lead to member double clean-up!!!*/ );
-
-        assert(!startsWith(makeUpperCopy(url), L"HTTPS:")); //not supported by wxHTTP!
-        const std::wstring urlFmt = startsWith(makeUpperCopy(url), L"HTTP://") ||
-                                    startsWith(makeUpperCopy(url), L"HTTPS://") ? afterFirst(url, L"://", IF_MISSING_RETURN_NONE) : url;
-        const std::wstring server =       beforeFirst(urlFmt, L'/', IF_MISSING_RETURN_ALL);
-        const std::wstring page   = L'/' + afterFirst(urlFmt, L'/', IF_MISSING_RETURN_NONE);
-
-#ifdef ZEN_WIN
-        //WinInet: 1. uses IE proxy settings! :) 2. follows HTTP redirects by default 3. swallows HTTPS if needed
-        hInternet_ = ::InternetOpen(userAgent.c_str(),            //_In_  LPCTSTR lpszAgent,
-                                    INTERNET_OPEN_TYPE_PRECONFIG, //_In_  DWORD dwAccessType,
-                                    nullptr, //_In_  LPCTSTR lpszProxyName,
-                                    nullptr, //_In_  LPCTSTR lpszProxyBypass,
-                                    0);      //_In_  DWORD dwFlags
-        if (!hInternet_)
-            THROW_LAST_SYS_ERROR(L"InternetOpen");
-
-        hSession_ = ::InternetConnect(hInternet_,     //_In_ HINTERNET     hInternet,
-                                      server.c_str(), //_In_ LPCTSTR       lpszServerName,
-                                      INTERNET_DEFAULT_HTTP_PORT, //_In_ INTERNET_PORT nServerPort,
-                                      nullptr,        //_In_ LPCTSTR       lpszUsername,
-                                      nullptr,        //_In_ LPCTSTR       lpszPassword,
-                                      INTERNET_SERVICE_HTTP, //_In_ DWORD         dwService,
-                                      0,              //_In_ DWORD         dwFlags,
-                                      0);             //_In_ DWORD_PTR     dwContext
-        if (!hSession_)
-            THROW_LAST_SYS_ERROR(L"InternetConnect");
-
-        const wchar_t* acceptTypes[] = { L"*/*", nullptr };
-        DWORD requestFlags =
-            //INTERNET_FLAG_KEEP_CONNECTION |
-            //      the combination 1. INTERNET_FLAG_KEEP_CONNECTION (= adds "Connection: Keep-Alive" but NOT "Keep-Alive: timeout" to the header)
-            //                      2. *no* "Keep-Alive: timeout" header entry 3. call from within VM and 4. *no* Fiddler running 5. HTTP POST
-            //      leads to Godaddy blocking the IP: http://www.freefilesync.org/forum/viewtopic.php?t=3855
-            //      => it seems a broken keep alive header is the trigger: But why is it then working outside the VM or when Fiddler is running??? Why not a problem for HTTP GET?
-            //          note: HTTP/1.1 has keep-alive semantics by default, so this flag is probably useless anyway
-            INTERNET_FLAG_NO_UI;
-
-        if (postParams)
-        {
-            requestFlags |= INTERNET_FLAG_NO_AUTO_REDIRECT; //POST would be re-issued as GET during auto-redirect => handle ourselves!
-        }
-        else //HTTP GET
-        {
-            requestFlags |= INTERNET_FLAG_IGNORE_REDIRECT_TO_HTTPS | INTERNET_FLAG_IGNORE_REDIRECT_TO_HTTP;
-            requestFlags |= INTERNET_FLAG_RELOAD; //not relevant for POST (= never cached)
-        }
-
-        hRequest_ = ::HttpOpenRequest(hSession_,    //_In_ HINTERNET hConnect,
-                                      postParams ? L"POST" : L"GET", //_In_ LPCTSTR   lpszVerb,
-                                      page.c_str(), //_In_ LPCTSTR   lpszObjectName,
-                                      nullptr,      //_In_ LPCTSTR   lpszVersion,
-                                      nullptr,      //_In_ LPCTSTR   lpszReferer,
-                                      acceptTypes,  //_In_ LPCTSTR   *lplpszAcceptTypes,
-                                      requestFlags, //_In_ DWORD     dwFlags,
-                                      0); //_In_ DWORD_PTR dwContext
-        if (!hRequest_)
-            THROW_LAST_SYS_ERROR(L"HttpOpenRequest");
-
-        const std::wstring headers = postParams ? L"Content-type: application/x-www-form-urlencoded" : L"";
-
-        assert(std::all_of(headers.begin(), headers.end(), [](wchar_t c) { return makeUnsigned(c) < 128; }));
-        //HttpSendRequest has finicky behavior for non-ASCII headers: https://msdn.microsoft.com/en-us/library/windows/desktop/aa384247
-
-        std::string postParamsBuf = postParams ? *postParams : "";
-
-        if (!::HttpSendRequest(hRequest_,             //_In_ HINTERNET hRequest,
-                               headers.c_str(),       //_In_ LPCTSTR   lpszHeaders,
-                               static_cast<DWORD>(headers.size()),                  //_In_ DWORD     dwHeadersLength,
-                               postParamsBuf.empty() ? nullptr : &postParamsBuf[0], //_In_ LPVOID    lpOptional,
-                               static_cast<DWORD>(postParamsBuf.size())))           //_In_ DWORD     dwOptionalLength
-            THROW_LAST_SYS_ERROR(L"HttpSendRequest");
-
-        DWORD sc = 0;
-        {
-            DWORD bufLen = sizeof(sc);
-            if (!::HttpQueryInfo(hRequest_, //_In_     HINTERNET hRequest,
-                                 HTTP_QUERY_STATUS_CODE | HTTP_QUERY_FLAG_NUMBER, //_In_     DWORD dwInfoLevel,
-                                 &sc,       //_Inout_  LPVOID lpvBuffer,
-                                 &bufLen,   //_Inout_  LPDWORD lpdwBufferLength,
-                                 nullptr))  //_Inout_  LPDWORD lpdwIndex
-                THROW_LAST_SYS_ERROR(L"HttpQueryInfo: HTTP_QUERY_STATUS_CODE");
-        }
-
-        //http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#3xx_Redirection
-        if (sc / 100 == 3) //e.g. 301, 302, 303, 307... we're not too greedy since we check location, too!
-        {
-            DWORD bufLen = 10000;
-            std::wstring location(bufLen, L'\0');
-            if (!::HttpQueryInfo(hRequest_, HTTP_QUERY_LOCATION, &*location.begin(), &bufLen, nullptr))
-                THROW_LAST_SYS_ERROR(L"HttpQueryInfo: HTTP_QUERY_LOCATION");
-            if (bufLen >= location.size()) //HttpQueryInfo expected to write terminating zero
-                throw SysError(L"HttpQueryInfo: HTTP_QUERY_LOCATION, buffer overflow");
-            location.resize(bufLen);
-
-            if (location.empty())
-                throw SysError(L"Unresolvable redirect. Empty target Location.");
-
-            throw UrlRedirectError(location);
-        }
-
-        if (sc != HTTP_STATUS_OK) //200
-            throw SysError(replaceCpy<std::wstring>(L"HTTP status code %x.", L"%x", numberTo<std::wstring>(sc)));
-        //e.g. 404 - HTTP_STATUS_NOT_FOUND
-
-#else
-        assert(std::this_thread::get_id() == mainThreadId);
-        assert(wxApp::IsMainLoopRunning());
-
-        webAccess_.SetHeader(L"User-Agent", userAgent);
-        webAccess_.SetTimeout(10 /*[s]*/); //default: 10 minutes: WTF are these wxWidgets people thinking???
-
-        if (!webAccess_.Connect(server)) //will *not* fail for non-reachable url here!
-            throw SysError(L"wxHTTP::Connect");
-
-        if (postParams)
-            if (!webAccess_.SetPostText(L"application/x-www-form-urlencoded", utfCvrtTo<wxString>(*postParams)))
-                throw SysError(L"wxHTTP::SetPostText");
-
-        httpStream_.reset(webAccess_.GetInputStream(page)); //pass ownership
-        const int sc = webAccess_.GetResponse();
-
-        //http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#3xx_Redirection
-        if (sc / 100 == 3) //e.g. 301, 302, 303, 307... we're not too greedy since we check location, too!
-        {
-            const std::wstring newUrl(webAccess_.GetHeader(L"Location"));
-            if (newUrl.empty())
-                throw SysError(L"Unresolvable redirect. Empty target Location.");
-
-            throw UrlRedirectError(newUrl);
-        }
-
-        if (sc != 200) //HTTP_STATUS_OK
-            throw SysError(replaceCpy<std::wstring>(L"HTTP status code %x.", L"%x", numberTo<std::wstring>(sc)));
-
-        if (!httpStream_ || webAccess_.GetError() != wxPROTO_NOERR)
-            throw SysError(L"wxHTTP::GetError (" + numberTo<std::wstring>(webAccess_.GetError()) + L")");
-#endif
-    }
-
-    ~Impl() { cleanup(); }
-
-    size_t tryRead(void* buffer, size_t bytesToRead) //throw SysError; may return short, only 0 means EOF!
-    {
-        if (bytesToRead == 0) //"read() with a count of 0 returns zero" => indistinguishable from end of file! => check!
-            throw std::logic_error("Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));
-
-#ifdef ZEN_WIN
-        //"HttpQueryInfo() + HTTP_QUERY_CONTENT_LENGTH" not supported by all http servers...
-        DWORD bytesRead = 0;
-        if (!::InternetReadFile(hRequest_,   //_In_   HINTERNET hFile,
-                                buffer,      //_Out_  LPVOID lpBuffer,
-                                static_cast<DWORD>(bytesToRead), //_In_   DWORD dwNumberOfBytesToRead,
-                                &bytesRead)) //_Out_  LPDWORD lpdwNumberOfBytesRead
-            THROW_LAST_SYS_ERROR(L"InternetReadFile");
-#else
-        httpStream_->Read(buffer, bytesToRead);
-
-        const wxStreamError ec = httpStream_->GetLastError();
-        if (ec != wxSTREAM_NO_ERROR && ec != wxSTREAM_EOF)
-            throw SysError(L"wxInputStream::GetLastError (" + numberTo<std::wstring>(httpStream_->GetLastError()) + L")");
-
-        const size_t bytesRead = httpStream_->LastRead();
-        //"if there are not enough bytes in the stream right now, LastRead() value will be
-        // less than size but greater than 0. If it is 0, it means that EOF has been reached."
-        assert(bytesRead > 0 || ec == wxSTREAM_EOF);
-#endif
-        if (bytesRead > bytesToRead) //better safe than sorry
-            throw SysError(L"InternetReadFile: buffer overflow.");
-
-        return bytesRead; //"zero indicates end of file"
-    }
-
-private:
-    Impl           (const Impl&) = delete;
-    Impl& operator=(const Impl&) = delete;
-
-    void cleanup()
-    {
-#ifdef ZEN_WIN
-        if (hRequest_ ) ::InternetCloseHandle(hRequest_);
-        if (hSession_ ) ::InternetCloseHandle(hSession_);
-        if (hInternet_) ::InternetCloseHandle(hInternet_);
-#endif
-    }
-
-#ifdef ZEN_WIN
-    HINTERNET hInternet_ = nullptr;
-    HINTERNET hSession_  = nullptr;
-    HINTERNET hRequest_  = nullptr;
-#else
-    wxHTTP webAccess_;
-    std::unique_ptr<wxInputStream> httpStream_; //must be deleted BEFORE webAccess is closed
-#endif
-};
-
-
-HttpInputStream::HttpInputStream(std::unique_ptr<Impl>&& pimpl) : pimpl_(std::move(pimpl)) {}
-
-HttpInputStream::~HttpInputStream() {}
-
-size_t HttpInputStream::tryRead(void* buffer, size_t bytesToRead) { return pimpl_->tryRead(buffer, bytesToRead); } //throw SysError
-
-
-std::string HttpInputStream::readAll() //throw SysError
-{
-    std::string buffer;
-    const size_t blockSize = getBlockSize();
-
-    for (;;)
-    {
-        buffer.resize(buffer.size() + blockSize);
-
-        const size_t bytesRead = pimpl_->tryRead(&*(buffer.end() - blockSize), blockSize); //throw SysError
-
-        if (bytesRead < blockSize)
-            buffer.resize(buffer.size() - (blockSize - bytesRead)); //caveat: unsigned arithmetics
-
-        if (bytesRead == 0)
-            return buffer;
-    }
-}
-
-
-namespace
-{
-std::unique_ptr<HttpInputStream::Impl> sendHttpRequestImpl(const std::wstring& url, const std::wstring& userAgent, //throw SysError
-                                                           const std::string* postParams) //issue POST if bound, GET otherwise
-{
-    std::wstring urlRed =  url;
-    //"A user agent should not automatically redirect a request more than five times, since such redirections usually indicate an infinite loop."
-    for (int redirects = 0; redirects < 6; ++redirects)
-        try
-        {
-            return std::make_unique<HttpInputStream::Impl>(urlRed, userAgent, postParams); //throw SysError, UrlRedirectError
-        }
-        catch (const UrlRedirectError& e) { urlRed = e.newUrl; }
-    throw SysError(L"Too many redirects.");
-}
-
-
-//encode into "application/x-www-form-urlencoded"
-std::string urlencode(const std::string& str)
-{
-    std::string out;
-    for (const char c : str) //follow PHP spec: https://github.com/php/php-src/blob/master/ext/standard/url.c#L500
-        if (c == ' ')
-            out += '+';
-        else if (('0' <= c && c <= '9') ||
-                 ('A' <= c && c <= 'Z') ||
-                 ('a' <= c && c <= 'z') ||
-                 c == '-' || c == '.' || c == '_') //note: "~" is encoded by PHP!
-            out += c;
-        else
-        {
-            const std::pair<char, char> hex = hexify(c);
-
-            out += '%';
-            out += hex.first;
-            out += hex.second;
-        }
-    return out;
-}
-
-
-std::string urldecode(const std::string& str)
-{
-    std::string out;
-    for (size_t i = 0; i < str.size(); ++i)
-    {
-        const char c = str[i];
-        if (c == '+')
-            out += ' ';
-        else if (c == '%' && str.size() - i >= 3 &&
-                 isHexDigit(str[i + 1]) &&
-                 isHexDigit(str[i + 2]))
-        {
-            out += unhexify(str[i + 1], str[i + 2]);
-            i += 2;
-        }
-        else
-            out += c;
-    }
-    return out;
-}
-}
-
-
-std::string zen::xWwwFormUrlEncode(const std::vector<std::pair<std::string, std::string>>& paramPairs)
-{
-    std::string output;
-    for (const auto& pair : paramPairs)
-        output += urlencode(pair.first) + '=' + urlencode(pair.second) + '&';
-    //encode both key and value: https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.1
-    if (!output.empty())
-        output.pop_back();
-    return output;
-}
-
-
-std::vector<std::pair<std::string, std::string>> zen::xWwwFormUrlDecode(const std::string& str)
-{
-    std::vector<std::pair<std::string, std::string>> output;
-
-    for (const std::string& nvPair : split(str, '&'))
-        if (!nvPair.empty())
-            output.emplace_back(urldecode(beforeFirst(nvPair, '=', IF_MISSING_RETURN_ALL)),
-                                urldecode(afterFirst (nvPair, '=', IF_MISSING_RETURN_NONE)));
-    return output;
-}
-
-
-HttpInputStream zen::sendHttpPost(const std::wstring& url, const std::wstring& userAgent,
-                                  const std::vector<std::pair<std::string, std::string>>& postParams) //throw SysError
-{
-    const std::string encodedParams = xWwwFormUrlEncode(postParams);
-    return sendHttpRequestImpl(url, userAgent, &encodedParams); //throw SysError
-}
-
-
-HttpInputStream zen::sendHttpGet(const std::wstring& url, const std::wstring& userAgent) //throw SysError
-{
-    return sendHttpRequestImpl(url, userAgent, nullptr); //throw SysError
-}
-
-
-bool zen::internetIsAlive() //noexcept
-{
-#ifdef ZEN_WIN
-    //::InternetAttemptConnect(0) -> not working as expected: succeeds even when there is no internet connection!
-
-    HINTERNET hInternet = ::InternetOpen(L"FreeFileSync", //_In_  LPCTSTR lpszAgent,
-                                         INTERNET_OPEN_TYPE_PRECONFIG, //_In_  DWORD dwAccessType,
-                                         nullptr, //_In_  LPCTSTR lpszProxyName,
-                                         nullptr, //_In_  LPCTSTR lpszProxyBypass,
-                                         0);      //_In_  DWORD dwFlags
-    if (!hInternet)
-        return false;
-    ZEN_ON_SCOPE_EXIT(::InternetCloseHandle(hInternet));
-
-    //InternetOpenUrl is shortcut for HTTP:GET with InternetConnect + HttpOpenRequest + HttpSendRequest:
-    HINTERNET hRequest = ::InternetOpenUrl(hInternet,   //_In_  HINTERNET hInternet,
-                                           L"http://www.google.com/", //_In_  LPCTSTR lpszUrl,
-                                           nullptr,     //_In_  LPCTSTR lpszHeaders,
-                                           0,           //_In_  DWORD dwHeadersLength,
-                                           INTERNET_FLAG_KEEP_CONNECTION |
-                                           INTERNET_FLAG_NO_UI  |
-                                           INTERNET_FLAG_RELOAD |
-                                           INTERNET_FLAG_NO_AUTO_REDIRECT, //_In_  DWORD dwFlags,
-                                           0);          //_In_  DWORD_PTR dwContext
-    //fails with ERROR_INTERNET_NAME_NOT_RESOLVED if server not found => the server-relative part is checked by HTTP_QUERY_STATUS_CODE!!!
-    if (!hRequest)
-        return false;
-    ZEN_ON_SCOPE_EXIT(::InternetCloseHandle(hRequest));
-
-    DWORD sc = 0;
-    {
-        DWORD bufLen = sizeof(sc);
-        if (!::HttpQueryInfo(hRequest, //_In_     HINTERNET hRequest,
-                             HTTP_QUERY_STATUS_CODE | HTTP_QUERY_FLAG_NUMBER, //_In_     DWORD dwInfoLevel,
-                             &sc,      //_Inout_  LPVOID lpvBuffer,
-                             &bufLen,  //_Inout_  LPDWORD lpdwBufferLength,
-                             nullptr)) //_Inout_  LPDWORD lpdwIndex
-            return false;
-    }
-
-#else
-    assert(std::this_thread::get_id() == mainThreadId);
-
-    const wxString server = L"www.google.com";
-    const wxString page   = L"/";
-
-    wxHTTP webAccess;
-    webAccess.SetTimeout(10 /*[s]*/); //default: 10 minutes: WTF are these wxWidgets people thinking???
-
-    if (!webAccess.Connect(server)) //will *not* fail for non-reachable url here!
-        return false;
-
-    std::unique_ptr<wxInputStream> httpStream(webAccess.GetInputStream(page)); //call before checking wxHTTP::GetResponse()
-    const int sc = webAccess.GetResponse();
-#endif
-    //attention: http://www.google.com/ might redirect to "https" => don't follow, just return "true"!!!
-    return sc / 100 == 2 || //e.g. 200
-           sc / 100 == 3;   //e.g. 301, 302, 303, 307... when in doubt, consider internet alive!
-}
+// *****************************************************************************

+// * This file is part of the FreeFileSync project. It is distributed under    *

+// * GNU General Public License: http://www.gnu.org/licenses/gpl-3.0           *

+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *

+// *****************************************************************************

+

+#include "http.h"

+

+    #include <wx/app.h>

+    #include <zen/thread.h> //std::thread::id

+    #include <wx/protocol/http.h>

+

+using namespace zen;

+

+

+namespace

+{

+

+struct UrlRedirectError

+{

+    UrlRedirectError(const std::wstring& url) : newUrl(url) {}

+    std::wstring newUrl;

+};

+}

+

+

+class HttpInputStream::Impl

+{

+public:

+    Impl(const std::wstring& url, const std::wstring& userAgent, const IOCallback& notifyUnbufferedIO, //throw SysError, UrlRedirectError

+         const std::string* postParams) : //issue POST if bound, GET otherwise

+        notifyUnbufferedIO_(notifyUnbufferedIO)

+    {

+        ZEN_ON_SCOPE_FAIL( cleanup(); /*destructor call would lead to member double clean-up!!!*/ );

+

+        assert(!startsWith(makeUpperCopy(url), L"HTTPS:")); //not supported by wxHTTP!

+        const std::wstring urlFmt = startsWith(makeUpperCopy(url), L"HTTP://") ||

+                                    startsWith(makeUpperCopy(url), L"HTTPS://") ? afterFirst(url, L"://", IF_MISSING_RETURN_NONE) : url;

+        const std::wstring server =       beforeFirst(urlFmt, L'/', IF_MISSING_RETURN_ALL);

+        const std::wstring page   = L'/' + afterFirst(urlFmt, L'/', IF_MISSING_RETURN_NONE);

+

+        assert(std::this_thread::get_id() == mainThreadId);

+        assert(wxApp::IsMainLoopRunning());

+

+        webAccess_.SetHeader(L"User-Agent", userAgent);

+        webAccess_.SetTimeout(10 /*[s]*/); //default: 10 minutes: WTF are these wxWidgets people thinking???

+

+        if (!webAccess_.Connect(server)) //will *not* fail for non-reachable url here!

+            throw SysError(L"wxHTTP::Connect");

+

+        if (postParams)

+            if (!webAccess_.SetPostText(L"application/x-www-form-urlencoded", utfCvrtTo<wxString>(*postParams)))

+                throw SysError(L"wxHTTP::SetPostText");

+

+        httpStream_.reset(webAccess_.GetInputStream(page)); //pass ownership

+        const int sc = webAccess_.GetResponse();

+

+        //http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#3xx_Redirection

+        if (sc / 100 == 3) //e.g. 301, 302, 303, 307... we're not too greedy since we check location, too!

+        {

+            const std::wstring newUrl(webAccess_.GetHeader(L"Location"));

+            if (newUrl.empty())

+                throw SysError(L"Unresolvable redirect. Empty target Location.");

+

+            throw UrlRedirectError(newUrl);

+        }

+

+        if (sc != 200) //HTTP_STATUS_OK

+            throw SysError(replaceCpy<std::wstring>(L"HTTP status code %x.", L"%x", numberTo<std::wstring>(sc)));

+

+        if (!httpStream_ || webAccess_.GetError() != wxPROTO_NOERR)

+            throw SysError(L"wxHTTP::GetError (" + numberTo<std::wstring>(webAccess_.GetError()) + L")");

+    }

+

+    ~Impl() { cleanup(); }

+

+    size_t read(void* buffer, size_t bytesToRead) //throw SysError, X; return "bytesToRead" bytes unless end of stream!

+    {

+        const size_t blockSize = getBlockSize();

+

+        while (memBuf_.size() < bytesToRead)

+        {

+            memBuf_.resize(memBuf_.size() + blockSize);

+            const size_t bytesRead = tryRead(&*(memBuf_.end() - blockSize), blockSize); //throw SysError; may return short, only 0 means EOF! => CONTRACT: bytesToRead > 0

+            memBuf_.resize(memBuf_.size() - blockSize + bytesRead); //caveat: unsigned arithmetics

+

+            if (notifyUnbufferedIO_) notifyUnbufferedIO_(bytesRead); //throw X

+

+            if (bytesRead == 0) //end of file

+                bytesToRead = memBuf_.size();

+        }

+

+        std::copy(memBuf_.begin(), memBuf_.begin() + bytesToRead, static_cast<char*>(buffer));

+        memBuf_.erase(memBuf_.begin(), memBuf_.begin() + bytesToRead);

+        return bytesToRead;

+    }

+

+    size_t getBlockSize() const { return 64 * 1024; }

+

+private:

+    size_t tryRead(void* buffer, size_t bytesToRead) //throw SysError; may return short, only 0 means EOF!

+    {

+        if (bytesToRead == 0) //"read() with a count of 0 returns zero" => indistinguishable from end of file! => check!

+            throw std::logic_error("Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));

+        assert(bytesToRead == getBlockSize());

+

+        httpStream_->Read(buffer, bytesToRead);

+

+        const wxStreamError ec = httpStream_->GetLastError();

+        if (ec != wxSTREAM_NO_ERROR && ec != wxSTREAM_EOF)

+            throw SysError(L"wxInputStream::GetLastError (" + numberTo<std::wstring>(httpStream_->GetLastError()) + L")");

+

+        const size_t bytesRead = httpStream_->LastRead();

+        //"if there are not enough bytes in the stream right now, LastRead() value will be

+        // less than size but greater than 0. If it is 0, it means that EOF has been reached."

+        assert(bytesRead > 0 || ec == wxSTREAM_EOF);

+        if (bytesRead > bytesToRead) //better safe than sorry

+            throw SysError(L"InternetReadFile: buffer overflow.");

+

+        return bytesRead; //"zero indicates end of file"

+    }

+

+    Impl           (const Impl&) = delete;

+    Impl& operator=(const Impl&) = delete;

+

+    void cleanup()

+    {

+    }

+

+    wxHTTP webAccess_;

+    std::unique_ptr<wxInputStream> httpStream_; //must be deleted BEFORE webAccess is closed

+

+    std::vector<char> memBuf_;

+    const IOCallback notifyUnbufferedIO_; //throw X

+};

+

+

+HttpInputStream::HttpInputStream(std::unique_ptr<Impl>&& pimpl) : pimpl_(std::move(pimpl)) {}

+

+HttpInputStream::~HttpInputStream() {}

+

+size_t HttpInputStream::read(void* buffer, size_t bytesToRead) { return pimpl_->read(buffer, bytesToRead); } //throw SysError, X; return "bytesToRead" bytes unless end of stream!

+

+size_t HttpInputStream::getBlockSize() const { return pimpl_->getBlockSize(); }

+

+std::string HttpInputStream::readAll() { return bufferedLoad<std::string>(*pimpl_); } //throw SysError, X;

+

+namespace

+{

+std::unique_ptr<HttpInputStream::Impl> sendHttpRequestImpl(const std::wstring& url, const std::wstring& userAgent, const IOCallback& notifyUnbufferedIO, //throw SysError

+                                                           const std::string* postParams) //issue POST if bound, GET otherwise

+{

+    std::wstring urlRed = url;

+    //"A user agent should not automatically redirect a request more than five times, since such redirections usually indicate an infinite loop."

+    for (int redirects = 0; redirects < 6; ++redirects)

+        try

+        {

+            return std::make_unique<HttpInputStream::Impl>(urlRed, userAgent, notifyUnbufferedIO, postParams); //throw SysError, UrlRedirectError

+        }

+        catch (const UrlRedirectError& e) { urlRed = e.newUrl; }

+    throw SysError(L"Too many redirects.");

+}

+

+

+//encode into "application/x-www-form-urlencoded"

+std::string urlencode(const std::string& str)

+{

+    std::string out;

+    for (const char c : str) //follow PHP spec: https://github.com/php/php-src/blob/master/ext/standard/url.c#L500

+        if (c == ' ')

+            out += '+';

+        else if (('0' <= c && c <= '9') ||

+                 ('A' <= c && c <= 'Z') ||

+                 ('a' <= c && c <= 'z') ||

+                 c == '-' || c == '.' || c == '_') //note: "~" is encoded by PHP!

+            out += c;

+        else

+        {

+            const std::pair<char, char> hex = hexify(c);

+

+            out += '%';

+            out += hex.first;

+            out += hex.second;

+        }

+    return out;

+}

+

+

+std::string urldecode(const std::string& str)

+{

+    std::string out;

+    for (size_t i = 0; i < str.size(); ++i)

+    {

+        const char c = str[i];

+        if (c == '+')

+            out += ' ';

+        else if (c == '%' && str.size() - i >= 3 &&

+                 isHexDigit(str[i + 1]) &&

+                 isHexDigit(str[i + 2]))

+        {

+            out += unhexify(str[i + 1], str[i + 2]);

+            i += 2;

+        }

+        else

+            out += c;

+    }

+    return out;

+}

+}

+

+

+std::string zen::xWwwFormUrlEncode(const std::vector<std::pair<std::string, std::string>>& paramPairs)

+{

+    std::string output;

+    for (const auto& pair : paramPairs)

+        output += urlencode(pair.first) + '=' + urlencode(pair.second) + '&';

+    //encode both key and value: https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.1

+    if (!output.empty())

+        output.pop_back();

+    return output;

+}

+

+

+std::vector<std::pair<std::string, std::string>> zen::xWwwFormUrlDecode(const std::string& str)

+{

+    std::vector<std::pair<std::string, std::string>> output;

+

+    for (const std::string& nvPair : split(str, '&'))

+        if (!nvPair.empty())

+            output.emplace_back(urldecode(beforeFirst(nvPair, '=', IF_MISSING_RETURN_ALL)),

+                                urldecode(afterFirst (nvPair, '=', IF_MISSING_RETURN_NONE)));

+    return output;

+}

+

+

+HttpInputStream zen::sendHttpPost(const std::wstring& url, const std::wstring& userAgent, const IOCallback& notifyUnbufferedIO,

+                                  const std::vector<std::pair<std::string, std::string>>& postParams) //throw SysError

+{

+    const std::string encodedParams = xWwwFormUrlEncode(postParams);

+    return sendHttpRequestImpl(url, userAgent, notifyUnbufferedIO, &encodedParams); //throw SysError

+}

+

+

+HttpInputStream zen::sendHttpGet(const std::wstring& url, const std::wstring& userAgent, const IOCallback& notifyUnbufferedIO) //throw SysError

+{

+    return sendHttpRequestImpl(url, userAgent, notifyUnbufferedIO, nullptr); //throw SysError

+}

+

+

+bool zen::internetIsAlive() //noexcept

+{

+    assert(std::this_thread::get_id() == mainThreadId);

+

+    const wxString server = L"www.google.com";

+    const wxString page   = L"/";

+

+    wxHTTP webAccess;

+    webAccess.SetTimeout(10 /*[s]*/); //default: 10 minutes: WTF are these wxWidgets people thinking???

+

+    if (!webAccess.Connect(server)) //will *not* fail for non-reachable url here!

+        return false;

+

+    std::unique_ptr<wxInputStream> httpStream(webAccess.GetInputStream(page)); //call before checking wxHTTP::GetResponse()

+    const int sc = webAccess.GetResponse();

+    //attention: http://www.google.com/ might redirect to "https" => don't follow, just return "true"!!!

+    return sc / 100 == 2 || //e.g. 200

+           sc / 100 == 3;   //e.g. 301, 302, 303, 307... when in doubt, consider internet alive!

+}