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authorErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
committerErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
commit84adefa331c4159d432d22840663c38f155cd4c1 (patch)
treebff9a9c66adda4df2106dfd0e5c053ab182a12bd /erts/example/next_perm.cc
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The R13B03 release.OTP_R13B03
Diffstat (limited to 'erts/example/next_perm.cc')
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diff --git a/erts/example/next_perm.cc b/erts/example/next_perm.cc
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+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2006-2009. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+/*
+ * Purpose: A driver using libpq to connect to Postgres
+ * from erlang, a sample for the driver documentation
+ */
+
+#include <erl_driver.h>
+
+#include <algorithm>
+#include <vector>
+
+using namespace std;
+
+#include <iostream>
+#define L cerr << __LINE__ << "\r\n";
+
+/* Driver interface declarations */
+static ErlDrvData start(ErlDrvPort port, char*);
+static void output(ErlDrvData drv_data, char *buf, int len);
+static void ready_async(ErlDrvData, ErlDrvThreadData);
+
+static ErlDrvEntry next_perm_driver_entry = {
+ NULL, /* init */
+ start,
+ NULL, /* stop */
+ output,
+ NULL, /* ready_input */
+ NULL, /* ready_output */
+ "next_perm", /* the name of the driver */
+ NULL, /* finish */
+ NULL, /* handle */
+ NULL, /* control */
+ NULL, /* timeout */
+ NULL, /* outputv */
+ ready_async,
+ NULL, /* flush */
+ NULL, /* call */
+ NULL /* event */
+};
+
+/* INITIALIZATION AFTER LOADING */
+
+/*
+ * This is the init function called after this driver has been loaded.
+ * It must *not* be declared static. Must return the address to
+ * the driver entry.
+ */
+
+#ifdef __cplusplus
+extern "C" { // shouldn't this be in the DRIVER_INIT macro?
+#endif
+DRIVER_INIT(next_perm)
+{
+ return &next_perm_driver_entry;
+}
+#ifdef __cplusplus
+}
+#endif
+
+/* DRIVER INTERFACE */
+static ErlDrvData start(ErlDrvPort port, char *)
+{
+ if (port == NULL)
+ return ERL_DRV_ERROR_GENERAL;
+ return (ErlDrvData)port;
+}
+
+
+struct our_async_data {
+ bool prev;
+ vector<int> data;
+ our_async_data(ErlDrvPort p, int command, const char* buf, int len);
+};
+
+our_async_data::our_async_data(ErlDrvPort p, int command,
+ const char* buf, int len)
+ : prev(command == 2),
+ data((int*)buf, (int*)buf + len / sizeof(int))
+{
+}
+
+static void do_perm(void* async_data);
+
+static void output(ErlDrvData drv_data, char *buf, int len)
+{
+ if (*buf < 1 || *buf > 2) return;
+ ErlDrvPort port = reinterpret_cast<ErlDrvPort>(drv_data);
+ void* async_data = new our_async_data(port, *buf, buf+1, len);
+ driver_async(port, NULL, do_perm, async_data, NULL);
+}
+
+static void do_perm(void* async_data)
+{
+ our_async_data* d = reinterpret_cast<our_async_data*>(async_data);
+ if (d->prev)
+ prev_permutation(d->data.begin(), d->data.end());
+ else
+ next_permutation(d->data.begin(), d->data.end());
+}
+
+static void ready_async(ErlDrvData drv_data, ErlDrvThreadData async_data)
+{
+ ErlDrvPort port = reinterpret_cast<ErlDrvPort>(drv_data);
+ our_async_data* d = reinterpret_cast<our_async_data*>(async_data);
+ int n = d->data.size(), result_n = n*2 + 5;
+ ErlDrvTermData* result = new ErlDrvTermData[result_n], * rp = result;
+ *rp++ = ERL_DRV_PORT;
+ *rp++ = driver_mk_port(port);
+ for (vector<int>::iterator i = d->data.begin();
+ i != d->data.end(); ++i) {
+ *rp++ = ERL_DRV_INT;
+ *rp++ = *i;
+ }
+ *rp++ = ERL_DRV_NIL;
+ *rp++ = ERL_DRV_LIST;
+ *rp++ = n+2;
+ driver_output_term(port, result, result_n);
+ delete[] result;
+ delete d;
+}