SERVER-29717 Add barebones mongodbcapi

4 files changed, 306 insertions, 0 deletions

diff --git a/src/mongo/client/SConscript b/src/mongo/client/SConscript
index d86fd987d1d..3d478ee246c 100644
--- a/src/mongo/client/SConscript
+++ b/src/mongo/client/SConscript
@@ -4,6 +4,16 @@ Import('env')
 
 env = env.Clone()
 
+
+env.SConscript(
+    dirs=[
+        'embedded',
+    ],
+    exports=[
+        'env',
+    ],
+)
+	
 # Contains only the core ConnectionString functionality, *not* the ability to call connect()
 # and return a DBClientBase* back. For that you need to link against the 'clientdriver' library.
 env.Library(
diff --git a/src/mongo/client/embedded/SConscript b/src/mongo/client/embedded/SConscript
new file mode 100644
index 00000000000..b4c435c09b0
--- /dev/null
+++ b/src/mongo/client/embedded/SConscript
@@ -0,0 +1,16 @@
+# -*- mode: python; -*-
+
+Import("env")
+
+env = env.Clone()
+
+capi = env.Library(
+    target='mongo_embedded_capi',
+    source=[
+        'libmongodbcapi.cpp',
+    ],
+    LIBDEPS=[]
+)
+
+env.Alias( 'embedded_capi', capi)
+
diff --git a/src/mongo/client/embedded/libmongodbcapi.cpp b/src/mongo/client/embedded/libmongodbcapi.cpp
new file mode 100644
index 00000000000..45e0d6a7913
--- /dev/null
+++ b/src/mongo/client/embedded/libmongodbcapi.cpp
@@ -0,0 +1,150 @@
+/**
+ *    Copyright (C) 2017 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects
+ *    for all of the code used other than as permitted herein. If you modify
+ *    file(s) with this exception, you may extend this exception to your
+ *    version of the file(s), but you are not obligated to do so. If you do not
+ *    wish to do so, delete this exception statement from your version. If you
+ *    delete this exception statement from all source files in the program,
+ *    then also delete it in the license file.
+ */
+
+#include "mongo/client/embedded/libmongodbcapi.h"
+
+#include <exception>
+#include <unordered_map>
+#include <vector>
+
+#include "mongo/stdx/memory.h"
+#include "mongo/stdx/unordered_map.h"
+#include "mongo/util/assert_util.h"
+
+struct libmongodbcapi_db {
+    libmongodbcapi_db() = default;
+
+    libmongodbcapi_db(const libmongodbcapi_db&) = delete;
+    libmongodbcapi_db& operator=(const libmongodbcapi_db&) = delete;
+
+    void* db_sc = nullptr;
+    mongo::stdx::unordered_map<libmongodbcapi_client*, std::unique_ptr<libmongodbcapi_client>>
+        open_clients;
+};
+struct libmongodbcapi_client {
+    libmongodbcapi_client(libmongodbcapi_db* db) : parent_db(db) {}
+
+    libmongodbcapi_client(const libmongodbcapi_client&) = delete;
+    libmongodbcapi_client& operator=(const libmongodbcapi_client&) = delete;
+
+    void* client_handle = nullptr;
+    std::vector<unsigned char> output;
+    libmongodbcapi_db* parent_db = nullptr;
+};
+
+namespace mongo {
+namespace {
+
+libmongodbcapi_db* global_db = nullptr;
+thread_local int last_error = LIBMONGODB_CAPI_ERROR_SUCCESS;
+
+libmongodbcapi_db* db_new(int argc, const char** argv, const char** envp) noexcept try {
+    last_error = LIBMONGODB_CAPI_ERROR_SUCCESS;
+    if (global_db) {
+        throw std::runtime_error("DB already exists");
+    }
+    global_db = new libmongodbcapi_db;
+    return global_db;
+} catch (const std::exception& e) {
+    last_error = LIBMONGODB_CAPI_ERROR_UNKNOWN;
+    return nullptr;
+}
+
+void db_destroy(libmongodbcapi_db* db) noexcept {
+    delete db;
+    invariant(!db || db == global_db);
+    if (db) {
+        global_db = nullptr;
+    }
+}
+
+int db_pump(libmongodbcapi_db* db) noexcept try {
+    return LIBMONGODB_CAPI_ERROR_SUCCESS;
+} catch (const std::exception& e) {
+    return LIBMONGODB_CAPI_ERROR_UNKNOWN;
+}
+
+libmongodbcapi_client* client_new(libmongodbcapi_db* db) noexcept try {
+    auto new_client = stdx::make_unique<libmongodbcapi_client>(db);
+    libmongodbcapi_client* rv = new_client.get();
+    db->open_clients.insert(std::make_pair(rv, std::move(new_client)));
+    return rv;
+} catch (const std::exception& e) {
+    return nullptr;
+}
+
+void client_destroy(libmongodbcapi_client* client) noexcept {
+    if (!client) {
+        return;
+    }
+    client->parent_db->open_clients.erase(client);
+}
+
+int client_wire_protocol_rpc(libmongodbcapi_client* client,
+                             const void* input,
+                             size_t input_size,
+                             void** output,
+                             size_t* output_size) noexcept {
+    return LIBMONGODB_CAPI_ERROR_SUCCESS;
+}
+
+int get_last_error() noexcept {
+    return last_error;
+}
+}  // namespace
+}  // namespace mongo
+
+extern "C" {
+libmongodbcapi_db* libmongodbcapi_db_new(int argc, const char** argv, const char** envp) {
+    return mongo::db_new(argc, argv, envp);
+}
+
+void libmongodbcapi_db_destroy(libmongodbcapi_db* db) {
+    return mongo::db_destroy(db);
+}
+
+int libmongodbcapi_db_pump(libmongodbcapi_db* p) {
+    return mongo::db_pump(p);
+}
+
+libmongodbcapi_client* libmongdbcapi_db_client_new(libmongodbcapi_db* db) {
+    return mongo::client_new(db);
+}
+
+void libmongdbcapi_db_client_destroy(libmongodbcapi_client* client) {
+    return mongo::client_destroy(client);
+}
+
+int libmongdbcapi_db_client_wire_protocol_rpc(libmongodbcapi_client* client,
+                                              const void* input,
+                                              size_t input_size,
+                                              void** output,
+                                              size_t* output_size) {
+    return mongo::client_wire_protocol_rpc(client, input, input_size, output, output_size);
+}
+}
diff --git a/src/mongo/client/embedded/libmongodbcapi.h b/src/mongo/client/embedded/libmongodbcapi.h
new file mode 100644
index 00000000000..2463bc784a7
--- /dev/null
+++ b/src/mongo/client/embedded/libmongodbcapi.h
@@ -0,0 +1,130 @@
+/**
+ *    Copyright (C) 2017 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects
+ *    for all of the code used other than as permitted herein. If you modify
+ *    file(s) with this exception, you may extend this exception to your
+ *    version of the file(s), but you are not obligated to do so. If you do not
+ *    wish to do so, delete this exception statement from your version. If you
+ *    delete this exception statement from all source files in the program,
+ *    then also delete it in the license file.
+ */
+#ifndef LIBMONGODBCAPI_H
+#define LIBMONGODBCAPI_H
+
+#include <stddef.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct libmongodbcapi_db libmongodbcapi_db;
+typedef struct libmongodbcapi_client libmongodbcapi_client;
+
+typedef enum {
+    LIBMONGODB_CAPI_ERROR_UNKNOWN = -1,
+    LIBMONGODB_CAPI_ERROR_SUCCESS
+} libmongodbcapi_error;
+
+/**
+* Starts the database and returns a handle with the service context.
+*
+* @param argc
+*      The number of arguments in argv
+* @param argv
+*      The arguments that will be passed to mongod at startup to initialize state
+* @param envp
+*      Environment variables that will be passed to mongod at startup to initilize state
+*
+* @return A pointer to a db handle or null on error
+*/
+libmongodbcapi_db* libmongodbcapi_db_new(int argc, const char** argv, const char** envp);
+
+/**
+* Shuts down the database
+*
+* @param
+*       A pointer to a db handle to be destroyed
+*/
+void libmongodbcapi_db_destroy(libmongodbcapi_db* db);
+
+/**
+* Let the database do background work. Returns an int from the error enum
+*
+* @param
+*      The database that has work that needs to be done
+*
+* @return A libmongo error code
+*/
+int libmongodbcapi_db_pump(libmongodbcapi_db* db);
+
+/**
+* Creates a new clienst and retuns it so the caller can do operation
+* A client will be destroyed when the owning db is destroyed
+*
+* @param db
+*      The datadase that will own this client and execute its RPC calls
+*
+* @return A pointer to a client or null on error
+*/
+libmongodbcapi_client* libmongodbcapi_db_client_new(libmongodbcapi_db* db);
+
+/**
+* Destroys a client and removes it from the db/service context
+* Cannot be called after the owning db is destroyed
+*
+* @param client
+*       A pointer to the client to be destroyed
+*/
+void libmongodbcapi_db_client_destroy(libmongodbcapi_client* client);
+
+/**
+* Makes an RPC call to the database
+*
+* @param client
+*      The client that will be performing the query on the database
+* @param input
+*      The query to be sent to and then executed by the database
+* @param input_size
+*      The size (number of bytes) of the input query
+* @param output
+*      A pointer to a void * where the database can write the location of the output.
+*      The library will manage the memory pointer to by *output.
+*      @TODO document lifetime of this buffer
+* @param output_size
+*      A pointer to a location where this function will write the size (number of bytes)
+*      of the output
+*
+* @return A success or error code
+*/
+int libmongodbcapi_db_client_wire_protocol_rpc(libmongodbcapi_client* client,
+                                               const void* input,
+                                               size_t input_size,
+                                               void** output,
+                                               size_t* output_size);
+/**
+* @return a per-thread value indicating the last error
+*/
+int libmongodbcapi_get_last_error();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif