ncbi_pipe_connector.cpp

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/* $Id: ncbi_pipe_connector.cpp 97266 2022-06-30 14:11:07Z lavr $
 * ===========================================================================
 *
 *                            PUBLIC DOMAIN NOTICE
 *               National Center for Biotechnology Information
 *
 *  This software/database is a "United States Government Work" under the
 *  terms of the United States Copyright Act.  It was written as part of
 *  the author's official duties as a United States Government employee and
 *  thus cannot be copyrighted.  This software/database is freely available
 *  to the public for use. The National Library of Medicine and the U.S.
 *  Government have not placed any restriction on its use or reproduction.
 *
 *  Although all reasonable efforts have been taken to ensure the accuracy
 *  and reliability of the software and data, the NLM and the U.S.
 *  Government do not and cannot warrant the performance or results that
 *  may be obtained by using this software or data. The NLM and the U.S.
 *  Government disclaim all warranties, express or implied, including
 *  warranties of performance, merchantability or fitness for any particular
 *  purpose.
 *
 *  Please cite the author in any work or product based on this material.
 *
 * ===========================================================================
 *
 * Author:  Denis Vakatov, Anton Lavrentiev, Vladimir Ivanov
 *
 * File Description:
 *   Implement CONNECTOR for a pipe interprocess communication
 *   (based on the NCBI CPipe).
 *
 *   See in "connectr.h" for the detailed specification of the underlying
 *   connector("CONNECTOR", "SConnectorTag") methods and structures.
 *
 */
 
#include <ncbi_pch.hpp>
#include "ncbi_ansi_ext.h"
#include <connect/ncbi_pipe_connector.hpp>
 
 
USING_NCBI_SCOPE;
 
 
/***********************************************************************
 *  INTERNAL -- Auxiliary types and static functions
 ***********************************************************************/
 
// All internal data necessary to perform the (re)connect and i/o
typedef struct {
    CPipe*              pipe;       // pipe handle; non-NULL
    string              cmd;        // program to execute
    vector<string>      args;       // program arguments
    CPipe::TCreateFlags flags;      // pipe create flags
    bool                own_pipe;   // true if pipe is owned
    size_t              pipe_size;  // pipe size
} SPipeConnector;
 
 
/***********************************************************************
 *  INTERNAL -- "s_VT_*" functions for the "virt. table" of connector methods
 ***********************************************************************/
 
 
extern "C" {
 
 
static const char* s_VT_GetType
(CONNECTOR /*connector*/)
{
    return "PIPE";
}
 
 
static char* s_VT_Descr(CONNECTOR connector)
{
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    string cmd_line(xxx->cmd);
    for (auto arg : xxx->args) {
        if ( !cmd_line.empty() ) {
            cmd_line += ' ';
        }
        string quote;
        bool replace = false;
        if (arg.find(' ')         == NPOS) {
            ;
        } else if (arg.find('"')  == NPOS) {
            quote = string(1, '"');
        } else if (arg.find('\'') == NPOS) {
            quote = string(1, '\'');
        } else {
            quote = string(1, '"');
            replace = true;
        }
        string tmp;
        if (replace) {
            tmp = arg;
            _ASSERT(!quote.empty());
            NStr::ReplaceInPlace(tmp, quote, '\\' + quote);
        }
        if ( !quote.empty() ) {
            cmd_line += quote;
        }
        cmd_line     += replace ? tmp : arg;
        if ( !quote.empty() ) {
            cmd_line += quote;
        }
    }
    return strdup(cmd_line.c_str());
}
 
 
static EIO_Status s_VT_Open
(CONNECTOR       connector,
 const STimeout* /*timeout*/)
{
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    return xxx->pipe->Open(xxx->cmd, xxx->args, xxx->flags,
                           kEmptyStr, NULL, xxx->pipe_size);
}
 
 
static EIO_Status s_VT_Wait
(CONNECTOR       connector,
 EIO_Event       event,
 const STimeout* timeout)
{
    _ASSERT(timeout != kDefaultTimeout);
    _ASSERT(event == eIO_Read  ||  event == eIO_Write);
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    CPipe::TChildPollMask what = 0;
    if (event & eIO_Read) {
        what |= CPipe::fDefault;
    }
    if (event & eIO_Write) {
        what |= CPipe::fStdIn;
    }
    return xxx->pipe->Poll(what, timeout) ? eIO_Success : eIO_Unknown;
}
 
 
static EIO_Status s_VT_Write
(CONNECTOR       connector,
 const void*     buf,
 size_t          size,
 size_t*         n_written,
 const STimeout* timeout)
{
    _ASSERT(timeout != kDefaultTimeout);
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    _VERIFY(xxx->pipe->SetTimeout(eIO_Write, timeout) == eIO_Success);
    return xxx->pipe->Write(buf, size, n_written);
}
 
 
static EIO_Status s_VT_Read
(CONNECTOR       connector,
 void*           buf,
 size_t          size,
 size_t*         n_read,
 const STimeout* timeout)
{
    _ASSERT(timeout != kDefaultTimeout);
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    _VERIFY(xxx->pipe->SetTimeout(eIO_Read, timeout) == eIO_Success);
    return xxx->pipe->Read(buf, size, n_read);
}
 
 
static EIO_Status s_VT_Status
(CONNECTOR connector,
 EIO_Event dir)
{
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    return xxx->pipe->Status(dir);
}
 
 
static EIO_Status s_VT_Close
(CONNECTOR       connector,
 const STimeout* timeout)
{
    _ASSERT(timeout != kDefaultTimeout);
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    _VERIFY(xxx->pipe->SetTimeout(eIO_Close, timeout) == eIO_Success);
    return xxx->pipe->Close();
}
 
 
static void s_Setup
(CONNECTOR connector)
{
    SMetaConnector* meta = connector->meta;
 
    // Initialize virtual table
    CONN_SET_METHOD(meta, get_type, s_VT_GetType, connector);
    CONN_SET_METHOD(meta, descr,    s_VT_Descr,   connector);
    CONN_SET_METHOD(meta, open,     s_VT_Open,    connector);
    CONN_SET_METHOD(meta, wait,     s_VT_Wait,    connector);
    CONN_SET_METHOD(meta, write,    s_VT_Write,   connector);
    CONN_SET_METHOD(meta, flush,    0,            0);
    CONN_SET_METHOD(meta, read,     s_VT_Read,    connector);
    CONN_SET_METHOD(meta, status,   s_VT_Status,  connector);
    CONN_SET_METHOD(meta, close,    s_VT_Close,   connector);
    meta->default_timeout = kInfiniteTimeout;
}
 
 
static void s_Destroy
(CONNECTOR connector)
{
    SPipeConnector* xxx = (SPipeConnector*) connector->handle;
    connector->handle = 0;
 
    _ASSERT(xxx->pipe);
    if (xxx->own_pipe) {
        delete xxx->pipe;
    }
    xxx->pipe = 0;
    delete xxx;
    free(connector);
}
 
 
} /* extern "C" */
 
 
BEGIN_NCBI_SCOPE
 
 
/***********************************************************************
 *  EXTERNAL -- the connector's "constructors"
 ***********************************************************************/
 
extern CONNECTOR PIPE_CreateConnector
(const string&         cmd,
 const vector<string>& args,
 CPipe::TCreateFlags   flags,
 CPipe*                pipe,
 EOwnership            own_pipe,
 size_t                pipe_size)
{
    auto ccc = make_c_unique((SConnector*) malloc(sizeof(SConnector)));
    if (!ccc) {
        return 0;
    }
 
    // Initialize internal data structures
    unique_ptr<SPipeConnector> xxx(new SPipeConnector);
    xxx->cmd       = cmd;
    xxx->args      = args;
    xxx->flags     = flags;
    xxx->pipe      = pipe ? pipe                       : new CPipe;
    xxx->own_pipe  = pipe ? own_pipe == eTakeOwnership : true;
    xxx->pipe_size = pipe_size;
 
    // Initialize connector data
    ccc->handle  = xxx.release();
    ccc->next    = 0;
    ccc->meta    = 0;
    ccc->setup   = s_Setup;
    ccc->destroy = s_Destroy;
 
    return ccc.release();
}
 
 
END_NCBI_SCOPE