diff src/plugincandidates.cpp @ 8:25e00373f597

Much renaming to ease inclusion into another project

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plugincandidates.cpp	Thu Apr 14 16:52:19 2016 +0100
@@ -0,0 +1,235 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+/*
+    Copyright (c) 2016 Queen Mary, University of London
+
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+    Except as contained in this notice, the names of the Centre for
+    Digital Music and Queen Mary, University of London shall not be
+    used in advertising or otherwise to promote the sale, use or other
+    dealings in this Software without prior written authorization.
+*/
+
+#include "plugincandidates.h"
+
+#include <set>
+#include <stdexcept>
+#include <iostream>
+
+#include <QProcess>
+#include <QDir>
+#include <QTime>
+
+#if defined(_WIN32)
+#define PLUGIN_GLOB "*.dll"
+#elif defined(__APPLE__)
+#define PLUGIN_GLOB "*.dylib *.so"
+#else
+#define PLUGIN_GLOB "*.so"
+#endif
+
+using namespace std;
+
+PluginCandidates::PluginCandidates(string helperExecutableName) :
+    m_helper(helperExecutableName),
+    m_logCallback(0)
+{
+}
+
+void
+PluginCandidates::setLogCallback(LogCallback *cb)
+{
+    m_logCallback = cb;
+}
+
+vector<string>
+PluginCandidates::getCandidateLibrariesFor(string tag) const
+{
+    if (m_candidates.find(tag) == m_candidates.end()) return {};
+    else return m_candidates.at(tag);
+}
+
+vector<PluginCandidates::FailureRec>
+PluginCandidates::getFailedLibrariesFor(string tag) const
+{
+    if (m_failures.find(tag) == m_failures.end()) return {};
+    else return m_failures.at(tag);
+}
+
+void
+PluginCandidates::log(string message)
+{
+    if (m_logCallback) m_logCallback->log("PluginCandidates: " + message);
+}
+
+vector<string>
+PluginCandidates::getLibrariesInPath(vector<string> path)
+{
+    vector<string> candidates;
+
+    for (string dirname: path) {
+
+        log("scanning directory " + dirname + "\n");
+
+        QDir dir(dirname.c_str(), PLUGIN_GLOB,
+		 QDir::Name | QDir::IgnoreCase,
+		 QDir::Files | QDir::Readable);
+
+	for (unsigned int i = 0; i < dir.count(); ++i) {
+            QString soname = dir.filePath(dir[i]);
+            candidates.push_back(soname.toStdString());
+        }
+    }
+
+    return candidates;
+}
+
+void
+PluginCandidates::scan(string tag,
+		       vector<string> pluginPath,
+		       string descriptorSymbolName)
+{
+    vector<string> libraries = getLibrariesInPath(pluginPath);
+    vector<string> remaining = libraries;
+
+    int runlimit = 20;
+    int runcount = 0;
+    
+    vector<string> result;
+    
+    while (result.size() < libraries.size() && runcount < runlimit) {
+	vector<string> output = runHelper(remaining, descriptorSymbolName);
+	result.insert(result.end(), output.begin(), output.end());
+	int shortfall = int(remaining.size()) - int(output.size());
+	if (shortfall > 0) {
+	    // Helper bailed out for some reason presumably associated
+	    // with the plugin following the last one it reported
+	    // on. Add a failure entry for that one and continue with
+	    // the following ones.
+            string failed = *(remaining.rbegin() + shortfall - 1);
+            log("helper output ended before result for plugin " + failed + "\n");
+	    result.push_back("FAILURE|" + failed + "|Plugin load check failed or timed out");
+            remaining = vector<string>
+                (remaining.rbegin(), remaining.rbegin() + shortfall - 1);
+	}
+	++runcount;
+    }
+
+    recordResult(tag, result);
+}
+
+vector<string>
+PluginCandidates::runHelper(vector<string> libraries, string descriptor)
+{
+    vector<string> output;
+
+    log("running helper with following library list:\n");
+    for (auto &lib: libraries) log(lib + "\n");
+
+    QProcess process;
+    process.setReadChannel(QProcess::StandardOutput);
+    process.setProcessChannelMode(QProcess::ForwardedErrorChannel);
+    process.start(m_helper.c_str(), { descriptor.c_str() });
+    if (!process.waitForStarted()) {
+	cerr << "helper failed to start" << endl;
+	throw runtime_error("plugin load helper failed to start");
+    }
+    for (auto &lib: libraries) {
+	process.write(lib.c_str(), lib.size());
+	process.write("\n", 1);
+    }
+
+    QTime t;
+    t.start();
+    int timeout = 3000; // ms
+
+    int buflen = 4096;
+    bool done = false;
+    
+    while (!done) {
+	char buf[buflen];
+	qint64 linelen = process.readLine(buf, buflen);
+        if (linelen > 0) {
+            output.push_back(buf);
+            done = (output.size() == libraries.size());
+        } else if (linelen < 0) {
+            // error case
+            log("received error code while reading from helper\n");
+            done = true;
+	} else {
+            // no error, but no line read (could just be between
+            // lines, or could be eof)
+            done = (process.state() == QProcess::NotRunning);
+            if (!done) {
+                if (t.elapsed() > timeout) {
+                    // this is purely an emergency measure
+                    log("timeout: helper took too long, killing it\n");
+                    process.kill();
+                    done = true;
+                } else {
+                    process.waitForReadyRead(200);
+                }
+            }
+        }
+    }
+
+    if (process.state() != QProcess::NotRunning) {
+        process.close();
+        process.waitForFinished();
+    }
+	
+    return output;
+}
+
+void
+PluginCandidates::recordResult(string tag, vector<string> result)
+{
+    for (auto &r: result) {
+
+        QString s(r.c_str());
+        QStringList bits = s.split("|");
+
+        log("read output line from helper: " + r);
+        
+        if (bits.size() < 2 || bits.size() > 3) {
+            log("invalid output line (wrong number of |-separated fields)\n");
+            continue;
+        }
+
+        string status = bits[0].toStdString();
+        
+        string library = bits[1].toStdString();
+        if (bits.size() == 2) library = bits[1].trimmed().toStdString();
+
+        string message = "";
+        if (bits.size() > 2) message = bits[2].trimmed().toStdString();
+        
+        if (status == "SUCCESS") {
+            m_candidates[tag].push_back(library);
+
+        } else if (status == "FAILURE") {
+            m_failures[tag].push_back({ library, message });
+
+        } else {
+            log("unexpected status \"" + status + "\" in output line\n");
+        }
+    }
+}
+