path: root/camel/camel-stream-buffer.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/* camel-stream-buffer.c : Buffer any other other stream */

/* 
 *
 * Author : 
 *  Michael Zucchi <notzed@helixcode.com>
 *
 * Copyright 1999, 2000 HelixCode (http://www.helixcode.com) .
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */


#include <config.h>
#include "camel-stream-buffer.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include "camel-log.h"

static CamelStreamBufferClass *parent_class=NULL;

enum {
    BUF_USER = 1<<0,    /* user-supplied buffer, do not free */
};

#define BUF_SIZE 1024

static gint _read (CamelStream *stream, gchar *buffer, gint n);
static gint _write (CamelStream *stream, const gchar *buffer, gint n);
static void _flush (CamelStream *stream);
static gint _available (CamelStream *stream);
static gboolean _eos (CamelStream *stream);
static void _close (CamelStream *stream);

static void _finalize (GtkObject *object);
static void _destroy (GtkObject *object);

static void _init_vbuf(CamelStreamBuffer *sbf, CamelStream *s, CamelStreamBufferMode mode, char *buf, guint32 size);
static void _init(CamelStreamBuffer *sbuf, CamelStream *s, CamelStreamBufferMode mode);

static void
camel_stream_buffer_class_init (CamelStreamBufferClass *camel_stream_buffer_class)
{
    CamelStreamClass *camel_stream_class = CAMEL_STREAM_CLASS (camel_stream_buffer_class);
    GtkObjectClass *gtk_object_class = GTK_OBJECT_CLASS (camel_stream_buffer_class);

    parent_class = gtk_type_class (camel_stream_get_type ());
    
    /* virtual method definition */
    camel_stream_buffer_class->init = _init;
    camel_stream_buffer_class->init_vbuf = _init_vbuf;

    /* virtual method overload */
    camel_stream_class->read = _read;
    camel_stream_class->write = _write;
    camel_stream_class->flush = _flush;
    camel_stream_class->available = _available;
    camel_stream_class->eos = _eos;
    camel_stream_class->close = _close;

    gtk_object_class->finalize = _finalize;
    gtk_object_class->destroy = _destroy;

}

static void
camel_stream_buffer_init (gpointer   object,  gpointer   klass)
{
    CamelStreamBuffer *sbf = CAMEL_STREAM_BUFFER (object);

    sbf->flags = 0;
    sbf->size = BUF_SIZE;
    sbf->buf = g_malloc(BUF_SIZE);
    sbf->ptr = sbf->buf;
    sbf->end = sbf->buf;
    sbf->mode = CAMEL_STREAM_BUFFER_READ | CAMEL_STREAM_BUFFER_BUFFER;
    sbf->stream = 0;
}

GtkType
camel_stream_buffer_get_type (void)
{
    static GtkType camel_stream_buffer_type = 0;
    
    gdk_threads_enter ();
    if (!camel_stream_buffer_type)  {
        GtkTypeInfo camel_stream_buffer_info =  
        {
            "CamelStreamBuffer",
            sizeof (CamelStreamBuffer),
            sizeof (CamelStreamBufferClass),
            (GtkClassInitFunc) camel_stream_buffer_class_init,
            (GtkObjectInitFunc) camel_stream_buffer_init,
                /* reserved_1 */ NULL,
                /* reserved_2 */ NULL,
            (GtkClassInitFunc) NULL,
        };
        
        camel_stream_buffer_type = gtk_type_unique (camel_stream_get_type (), &camel_stream_buffer_info);
    }
    gdk_threads_leave ();
    return camel_stream_buffer_type;
}


static void           
_destroy (GtkObject *object)
{
    CamelStreamBuffer *stream_buffer = CAMEL_STREAM_BUFFER (object);
    
    CAMEL_LOG_FULL_DEBUG ("Entering CamelStreamBuffer::destroy\n");

    /* NOP to remove warnings */
    stream_buffer->buf = stream_buffer->buf;
    

    GTK_OBJECT_CLASS (parent_class)->destroy (object);
    
    CAMEL_LOG_FULL_DEBUG ("Leaving CamelStreamBuffer::destroy\n");
}


static void           
_finalize (GtkObject *object)
{
    CamelStreamBuffer *sbf = CAMEL_STREAM_BUFFER (object);


    CAMEL_LOG_FULL_DEBUG ("Entering CamelStreamBuffer::finalize\n");
    
    if (!(sbf->flags & BUF_USER)) {
        g_free(sbf->buf);
    }
    if (sbf->stream)
        gtk_object_unref(GTK_OBJECT(sbf->stream));
    
    GTK_OBJECT_CLASS (parent_class)->finalize (object);
    CAMEL_LOG_FULL_DEBUG ("Leaving CamelStreamBuffer::finalize\n");
}

static void
_set_vbuf(CamelStreamBuffer *sbf, char *buf, CamelStreamBufferMode mode, int size)
{
    if (sbf->buf && !(sbf->flags & BUF_USER)) {
        g_free(sbf->buf);
    }
    if (buf) {
        sbf->buf = buf;
        sbf->flags |= BUF_USER;
    } else {
        sbf->buf = g_malloc(size);
        sbf->flags &= ~BUF_USER;
    }
    sbf->size = size;
    sbf->mode = mode;
}

static void
_init_vbuf(CamelStreamBuffer *sbf, CamelStream *s, CamelStreamBufferMode mode, char *buf, guint32 size)
{
    _set_vbuf(sbf, buf, mode, size);
    if (sbf->stream)
        gtk_object_unref(GTK_OBJECT(sbf->stream));
    sbf->stream = s;
}

static void
_init(CamelStreamBuffer *sbuf, CamelStream *s, CamelStreamBufferMode mode)
{
    _init_vbuf(sbuf, s, mode, NULL, BUF_SIZE);
}


/**
 * camel_stream_buffer_new:
 * @stream: Existing stream to buffer.
 * @mode: Operational mode of buffered stream.
 * 
 * Create a new buffered stream of another stream.  A default
 * buffer size (1024 bytes), automatically managed will be used
 * for buffering.
 *
 * See camel_stream_buffer_new_with_vbuf() for details on the
 * @mode parameter.
 * 
 * Return value: A newly created buffered stream.
 **/
CamelStream *
camel_stream_buffer_new (CamelStream *stream, CamelStreamBufferMode mode)
{
    CamelStreamBuffer *sbf;
    sbf = gtk_type_new (camel_stream_buffer_get_type ());
    CAMEL_STREAM_BUFFER_CLASS (GTK_OBJECT(sbf)->klass)->init (sbf, stream, mode);
    
    return CAMEL_STREAM (sbf);
}

/**
 * camel_stream_buffer_new_with_vbuf:
 * @stream: An existing stream to buffer.
 * @mode: Mode to buffer in.
 * @buf: Memory to use for buffering.
 * @size: Size of buffer to use.
 * 
 * Create a new stream which buffers another stream, @stream.
 *
 * The following values are available for @mode:
 *
 * CAMEL_STREAM_BUFFER_BUFFER, Buffer the input/output in blocks.
 * CAMEL_STREAM_BUFFER_NEWLINE, Buffer on newlines (for output).
 * CAMEL_STREAM_BUFFER_NONE, Perform no buffering.
 *
 * Note that currently this is ignored and CAMEL_STREAM_BUFFER_BUFFER
 * is always used.
 *
 * In addition, one of the following mode options should be or'd
 * together with the buffering mode:
 *
 * CAMEL_STREAM_BUFFER_WRITE, Buffer in write mode.
 * CAMEL_STREAM_BUFFER_READ, Buffer in read mode.
 * 
 * Buffering can only be done in one direction for any
 * buffer instance.
 * 
 * If @buf is non-NULL, then use the memory pointed to
 * (for upto @size bytes) as the buffer for all buffering
 * operations.  It is upto the application to free this buffer.
 * If @buf is NULL, then allocate and manage @size bytes
 * for all buffering.
 *
 * Return value: A new stream with buffering applied.
 **/
CamelStream *camel_stream_buffer_new_with_vbuf (CamelStream *stream, CamelStreamBufferMode mode, char *buf, guint32 size)
{
    CamelStreamBuffer *sbf;
    sbf = gtk_type_new (camel_stream_buffer_get_type ());
    CAMEL_STREAM_BUFFER_CLASS (GTK_OBJECT(sbf)->klass)->init_vbuf (sbf, stream, mode, buf, size);
    
    return CAMEL_STREAM (sbf);  
}

/**
 * _read: read bytes from a stream
 * @stream: stream
 * @buffer: buffer where bytes are stored
 * @n: max number of bytes to read
 * 
 * 
 * 
 * Return value: number of bytes actually read.
 **/
static gint
_read (CamelStream *stream, gchar *buffer, gint n)
{
    CamelStreamBuffer *sbf = CAMEL_STREAM_BUFFER (stream);
    int bytes_read=1;
    int bytes_left;
    gchar *bptr = buffer;

    g_return_val_if_fail( (sbf->mode & CAMEL_STREAM_BUFFER_MODE) == CAMEL_STREAM_BUFFER_READ, 0);

    while (n && bytes_read>0) {
        bytes_left = sbf->end - sbf->ptr;
        if (bytes_left<n) {
            if (bytes_left>0) {
                memcpy(bptr, sbf->ptr, bytes_left);
                n -= bytes_left;
                bptr += bytes_left;
                sbf->ptr += bytes_left;
            }
            /* if we are reading a lot, then read directly to the destination buffer */
            if (n >= sbf->size/3) {
                bytes_read = camel_stream_read(sbf->stream, bptr, n);
                if (bytes_read>0) {
                    n -= bytes_read;
                    bptr += bytes_read;
                }
            } else {
                bytes_read = camel_stream_read(sbf->stream, sbf->buf, sbf->size);
                if (bytes_read>0) {
                    sbf->ptr = sbf->buf;
                    sbf->end = sbf->buf+bytes_read;
                    memcpy(bptr, sbf->ptr, n);
                    sbf->ptr += n;
                    bptr += n;
                    n -= bytes_read;
                }
            }
        } else {
            memcpy(bptr, sbf->ptr, bytes_left);
            sbf->ptr += n;
            bptr += n;
            n = 0;
        }
    }

    return bptr-buffer;
}


static gint
_write (CamelStream *stream, const gchar *buffer, gint n)
{
    CamelStreamBuffer *sbf = CAMEL_STREAM_BUFFER (stream);
    const gchar *bptr = buffer;
    int bytes_written = 1;
    int bytes_left;

    g_return_val_if_fail( (sbf->mode & CAMEL_STREAM_BUFFER_MODE) == CAMEL_STREAM_BUFFER_WRITE, 0);

    while (n && bytes_written > 0) {
        bytes_left = sbf->size - (sbf->ptr-sbf->buf);
        if (bytes_left<n) {
            memcpy(sbf->ptr, bptr, bytes_left);
            n -= bytes_left;
            bptr += bytes_left;
            bytes_written = camel_stream_write(sbf->stream, sbf->buf, sbf->size);
            sbf->ptr = sbf->buf;
            /* if we are writing a lot, write directly to the stream */
            if (n >= sbf->size/3) {
                bytes_written = camel_stream_write(sbf->stream, bptr, n);
                bytes_written = n;
                n -= bytes_written;
                bptr += bytes_written;
            } else {
                memcpy(sbf->ptr, bptr, n);
                sbf->ptr += n;
                bptr += n;
                n = 0;
            }
        } else {
            memcpy(sbf->ptr, bptr, n);
            sbf->ptr += n;
            bptr += n;
            n = 0;
        }
    }
    return 0;
}



static void
_flush (CamelStream *stream)
{
    CamelStreamBuffer *sbf = CAMEL_STREAM_BUFFER (stream);

    if ((sbf->mode & CAMEL_STREAM_BUFFER_MODE) == CAMEL_STREAM_BUFFER_WRITE) {
        int written = camel_stream_write(sbf->stream, sbf->buf, sbf->ptr-sbf->buf);
        if (written > 0) {
            sbf->ptr += written;
        }
    } else {
        /* nothing to do for read mode 'flush' */
    }

    camel_stream_flush(sbf->stream);
}



static gint 
_available (CamelStream *stream)
{
    /* unimplemented */
    return 0;
}


static gboolean
_eos (CamelStream *stream)
{
    CamelStreamBuffer *sbf = CAMEL_STREAM_BUFFER (stream);

    return camel_stream_eos(sbf->stream);
}

static void
_close (CamelStream *stream)
{
    CamelStreamBuffer *sbf = CAMEL_STREAM_BUFFER (stream);

    _flush(stream);
    camel_stream_close(sbf->stream);
}

/**
 * camel_stream_buffer_gets:
 * @sbf: A CamelStreamBuffer.
 * @buf: Memory to write the string to.
 * @max: Maxmimum number of characters to store.
 * 
 * Read a line of characters up to the next newline character or
 * @max characters.
 *
 * If the newline character is encountered, then it will be
 * included in the buffer @buf.  The buffer will be #NUL terminated.
 * 
 * Return value: The number of characters read, or 0 for end of file or
 * file error.
 **/
int camel_stream_buffer_gets(CamelStreamBuffer *sbf, char *buf, int max)
{
    register char *outptr, *inptr, *inend, c, *outend;
    int bytes_read;

    outptr = buf;
    inptr = sbf->ptr;
    inend = sbf->end;
    outend = buf+max-1; /* room for NUL */

    do {
        while (inptr<inend && outptr<outend) {
            c = *inptr++;
            *outptr++ = c;
            if (c=='\n') {
                *outptr = 0;
                sbf->ptr = inptr;
                return outptr-buf;
            }
        }
        if (outptr == outend)
            break;

        bytes_read = camel_stream_read(sbf->stream, sbf->buf, sbf->size);
        if (bytes_read>0) {
            inptr = sbf->ptr = sbf->buf;
            inend = sbf->end = sbf->buf + bytes_read;
        }
    } while (bytes_read>0);

    sbf->ptr = inptr;
    if (outptr<=outend)
        *outptr = 0;

    return outptr-buf;
}