/* -*- c-file-style: "ruby"; indent-tabs-mode: nil -*- */
#include "oci8.h"

static ID id_plus;
static ID id_dir_alias;
static ID id_filename;
static VALUE cOCI8LOB;
static VALUE cOCI8CLOB;
static VALUE cOCI8NCLOB;
static VALUE cOCI8BLOB;
static VALUE cOCI8BFILE;
static VALUE seek_set;
static VALUE seek_cur;
static VALUE seek_end;

enum state {
    S_NO_OPEN_CLOSE,
    S_OPEN,
    S_CLOSE,
    S_BFILE_CLOSE,
    S_BFILE_OPEN,
};
typedef struct {
    oci8_base_t base;
    VALUE svc;
    OCISvcCtx *svchp;
    ub4 pos;
    int char_width;
    ub1 csfrm;
    ub1 lobtype;
    enum state state;
} oci8_lob_t;

static VALUE oci8_lob_write(VALUE self, VALUE data);

static VALUE oci8_make_lob(VALUE klass, oci8_svcctx_t *svcctx, OCILobLocator *s)
{
    oci8_lob_t *lob;
    boolean is_temp;
    VALUE lob_obj;

    lob_obj = rb_funcall(klass, oci8_id_new, 1, svcctx->base.self);
    lob = DATA_PTR(lob_obj);
    /* If 's' is a temporary lob, use OCILobLocatorAssign instead. */
    chker2(OCILobIsTemporary(oci8_envhp, oci8_errhp, s, &is_temp), &svcctx->base);
    if (is_temp)
        chker2(OCILobLocatorAssign_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, s, &lob->base.hp.lob),
               &svcctx->base);
    else
        chker2(OCILobAssign(oci8_envhp, oci8_errhp, s, &lob->base.hp.lob),
               &svcctx->base);
    return lob_obj;
}

VALUE oci8_make_clob(oci8_svcctx_t *svcctx, OCILobLocator *s)
{
    return oci8_make_lob(cOCI8CLOB, svcctx, s);
}

VALUE oci8_make_nclob(oci8_svcctx_t *svcctx, OCILobLocator *s)
{
    return oci8_make_lob(cOCI8NCLOB, svcctx, s);
}

VALUE oci8_make_blob(oci8_svcctx_t *svcctx, OCILobLocator *s)
{
    return oci8_make_lob(cOCI8BLOB, svcctx, s);
}

VALUE oci8_make_bfile(oci8_svcctx_t *svcctx, OCILobLocator *s)
{
    return oci8_make_lob(cOCI8BFILE, svcctx, s);
}

static void oci8_assign_lob(VALUE klass, oci8_svcctx_t *svcctx, VALUE lob, OCILobLocator **dest)
{
    oci8_base_t *base = oci8_get_handle(lob, klass);
    chker2(OCILobLocatorAssign_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, base->hp.lob, dest), base);
}

void oci8_assign_clob(oci8_svcctx_t *svcctx, VALUE lob, OCILobLocator **dest)
{
    oci8_assign_lob(cOCI8CLOB, svcctx, lob, dest);
}

void oci8_assign_nclob(oci8_svcctx_t *svcctx, VALUE lob, OCILobLocator **dest)
{
    oci8_assign_lob(cOCI8NCLOB, svcctx, lob, dest);
}

void oci8_assign_blob(oci8_svcctx_t *svcctx, VALUE lob, OCILobLocator **dest)
{
    oci8_assign_lob(cOCI8BLOB, svcctx, lob, dest);
}

void oci8_assign_bfile(oci8_svcctx_t *svcctx, VALUE lob, OCILobLocator **dest)
{
    oci8_assign_lob(cOCI8BFILE, svcctx, lob, dest);
}

static void oci8_lob_mark(oci8_base_t *base)
{
    oci8_lob_t *lob = (oci8_lob_t *)base;
    rb_gc_mark(lob->svc);
}

static void oci8_lob_free(oci8_base_t *base)
{
    oci8_lob_t *lob = (oci8_lob_t *)base;
    boolean is_temporary;

    if (lob->svchp != NULL
        && OCILobIsTemporary(oci8_envhp, oci8_errhp, lob->base.hp.lob, &is_temporary) == OCI_SUCCESS
        && is_temporary) {

#ifdef HAVE_RB_THREAD_BLOCKING_REGION
        oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);
        oci8_temp_lob_t *temp_lob = ALLOC(oci8_temp_lob_t);

        temp_lob->next = svcctx->temp_lobs;
        temp_lob->lob = lob->base.hp.lob;
        svcctx->temp_lobs = temp_lob;
        lob->base.type = 0;
        lob->base.hp.ptr = NULL;
#else
        /* FIXME: This may stall the GC. */
        OCILobFreeTemporary(lob->svchp, oci8_errhp, lob->base.hp.lob);
#endif
    }
    lob->svc = Qnil;
    lob->svchp = NULL;
}

static oci8_base_vtable_t oci8_lob_vtable = {
    oci8_lob_mark,
    oci8_lob_free,
    sizeof(oci8_lob_t),
};

static ub4 oci8_lob_get_length(oci8_lob_t *lob)
{
    oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);
    ub4 len;

    chker2(OCILobGetLength_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, &len),
           &svcctx->base);
    return len;
}

static void lob_open(oci8_lob_t *lob)
{
    if (lob->state == S_CLOSE) {
        oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);

        chker2(OCILobOpen_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, OCI_DEFAULT),
               &svcctx->base);
        lob->state = S_OPEN;
    }
}

static void lob_close(oci8_lob_t *lob)
{
    if (lob->state == S_OPEN) {
        oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);

        chker2(OCILobClose_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob),
               &svcctx->base);
        lob->state = S_CLOSE;
    }
}

static void bfile_close(oci8_lob_t *lob)
{
    if (lob->state == S_BFILE_OPEN) {
        oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);

        chker2(OCILobFileClose_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob),
               &svcctx->base);
        lob->state = S_BFILE_CLOSE;
    }
}

/*
 *  Document-class: OCI8::LOB
 *
 *  This is the abstract base class of large-object data types; BFILE, BLOB, CLOB and NCLOB.
 *
 */

/*
 *  Document-class: OCI8::CLOB
 *
 */

/*
 *  Document-class: OCI8::NCLOB
 *
 */

/*
 *  Document-class: OCI8::BLOB
 *
 */

/*
 *  Document-class: OCI8::BFILE
 *
 *  @method truncate(length)
 *  @method size = length
 *  @method write(data)
 */

/*
 *  Closes the lob.
 *
 *  @return [self]
 */
static VALUE oci8_lob_close(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    lob_close(lob);
    oci8_base_free(DATA_PTR(self));
    return self;
}

static VALUE oci8_lob_do_initialize(int argc, VALUE *argv, VALUE self, ub1 csfrm, ub1 lobtype)
{
    oci8_lob_t *lob = DATA_PTR(self);
    VALUE svc;
    VALUE val;
    sword rv;

    rb_scan_args(argc, argv, "11", &svc, &val);
    TO_SVCCTX(svc); /* check argument type */
    rv = OCIDescriptorAlloc(oci8_envhp, &lob->base.hp.ptr, OCI_DTYPE_LOB, 0, NULL);
    if (rv != OCI_SUCCESS)
        oci8_env_raise(oci8_envhp, rv);
    lob->base.type = OCI_DTYPE_LOB;
    lob->svc = svc;
    lob->svchp = NULL;
    lob->pos = 0;
    lob->char_width = 1;
    lob->csfrm = csfrm;
    lob->lobtype = lobtype;
    lob->state = S_NO_OPEN_CLOSE;
    oci8_link_to_parent((oci8_base_t*)lob, (oci8_base_t*)DATA_PTR(svc));
    if (!NIL_P(val)) {
        oci8_svcctx_t *svcctx = oci8_get_svcctx(svc);
        OCI8StringValue(val);
        chker2(OCILobCreateTemporary_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, 0, csfrm, lobtype, TRUE, OCI_DURATION_SESSION),
               &svcctx->base);
        lob->svchp = oci8_get_oci_svcctx(svc);
        oci8_lob_write(self, val);
        lob->pos = 0; /* reset the position */
    }
    return Qnil;
}

/*
 *  call-seq:
 *    initialize(conn, contents = nil)
 *
 *  Creates a temporary CLOB when <i>contents</i> is not nil.
 *  Otherwise, it creates an uninitialized lob, which is used internally
 *  to fetch CLOB column data.
 *
 *  @example
 *    # Inserts a file name and its contents as CLOB.
 *    clob = OCI8::CLOB.new(conn, File.read(file_name))
 *    conn.exec('insert into file_contents values (:1, :2)', file_name, clob)
 *
 *  @param [OCI8] conn connection
 *  @param [String] contents
 *  @return [OCI8::CLOB]
 */
static VALUE oci8_clob_initialize(int argc, VALUE *argv, VALUE self)
{
    oci8_lob_do_initialize(argc, argv, self, SQLCS_IMPLICIT, OCI_TEMP_CLOB);
    return Qnil;
}

/*
 *  call-seq:
 *    initialize(conn, contents = nil)
 *
 *  Creates a temporary NCLOB when <i>contents</i> is not nil.
 *  Otherwise, it creates an uninitialized lob, which is used internally
 *  to fetch NCLOB column data.
 *
 *  @example
 *    # Inserts a file name and its contents as NCLOB.
 *    clob = OCI8::NCLOB.new(conn, File.read(file_name))
 *    conn.exec('insert into file_contents values (:1, :2)', file_name, clob)
 *
 *  @param [OCI8] conn
 *  @param [String] contents
 *  @return [OCI8::NCLOB]
 */
static VALUE oci8_nclob_initialize(int argc, VALUE *argv, VALUE self)
{
    oci8_lob_do_initialize(argc, argv, self, SQLCS_NCHAR, OCI_TEMP_CLOB);
    return Qnil;
}

/*
 *  call-seq:
 *    initialize(conn, contents = nil)
 *
 *  Creates a temporary BLOB when <i>contents</i> is not nil.
 *  Otherwise, it creates an uninitialized lob, which is used internally
 *  to fetch BLOB column data.
 *
 *  @example
 *    # Inserts a file name and its contents as BLOB.
 *    clob = OCI8::BLOB.new(conn, File.read(file_name, :mode => 'rb'))
 *    conn.exec('insert into file_contents values (:1, :2)', file_name, clob)
 *
 *  @param [OCI8] conn
 *  @param [String] contents
 *  @return [OCI8::BLOB]
 */
static VALUE oci8_blob_initialize(int argc, VALUE *argv, VALUE self)
{
    oci8_lob_do_initialize(argc, argv, self, SQLCS_IMPLICIT, OCI_TEMP_BLOB);
    return Qnil;
}

/*
 *  call-seq:
 *    __char_width = size
 *
 *  @private
 *  IMO, nobody need and use this.
 */
static VALUE oci8_lob_set_char_width(VALUE self, VALUE vsize)
{
    oci8_lob_t *lob = DATA_PTR(self);
    int size;

    size = NUM2INT(vsize); /* 1 */

    if (size <= 0)
        rb_raise(rb_eArgError, "size must be more than one.");
    lob->char_width = size;
    return vsize;
}

/*
 *  Returns +true+ when <i>self</i> is initialized.
 *
 *  @return [true or false]
 */
static VALUE oci8_lob_available_p(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    boolean is_initialized;

    chker2(OCILobLocatorIsInit(oci8_envhp, oci8_errhp, lob->base.hp.lob, &is_initialized),
           &lob->base);
    return is_initialized ? Qtrue : Qfalse;
}

/*
 *  Returns the size.
 *  For CLOB and NCLOB it is the number of characters,
 *  for BLOB and BFILE it is the number of bytes.
 *
 *  @return [Integer]
 */
static VALUE oci8_lob_get_size(VALUE self)
{
    return UB4_TO_NUM(oci8_lob_get_length(DATA_PTR(self)));
}

/*
 *  Returns the current offset.
 *  For CLOB and NCLOB it is the number of characters,
 *  for BLOB and BFILE it is the number of bytes.
 *
 *  @return [Integer]
 */
static VALUE oci8_lob_get_pos(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    return UB4_TO_NUM(lob->pos);
}

/*
 *  Returns true if the current offset is at end of lob.
 *
 *  @return [true or false]
 */
static VALUE oci8_lob_eof_p(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    if (oci8_lob_get_length(lob) < lob->pos)
        return Qfalse;
    else
        return Qtrue;
}

/*
 *  call-seq:
 *     seek(amount, whence=IO::SEEK_SET)
 *
 *  Seeks to the given offset in the stream. The new position, measured in characters,
 *  is obtained by adding offset <i>amount</i> to the position specified by <i>whence</i>.
 *  If <i>whence</i> is set to IO::SEEK_SET, IO::SEEK_CUR, or IO::SEEK_END,
 *  the offset is relative to the start of the file, the current position
 *  indicator, or end-of-file, respectively.
 *
 *  @param [Integer] amount
 *  @param [IO::SEEK_SET, IO::SEEK_CUR or IO::SEEK_END] whence
 *  @return [self]
 */
static VALUE oci8_lob_seek(int argc, VALUE *argv, VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    VALUE position, whence;

    rb_scan_args(argc, argv, "11", &position, &whence);
    if (argc == 2 && (whence != seek_set && whence != seek_cur && whence != seek_end)) {
        if (FIXNUM_P(whence)) {
            rb_raise(rb_eArgError, "expect IO::SEEK_SET, IO::SEEK_CUR or IO::SEEK_END but %d",
                     FIX2INT(whence));
        } else {
            rb_raise(rb_eArgError, "expect IO::SEEK_SET, IO::SEEK_CUR or IO::SEEK_END but %s",
                     rb_class2name(CLASS_OF(whence)));
        }
    }
    if (whence == seek_cur) {
        position = rb_funcall(UB4_TO_NUM(lob->pos), id_plus, 1, position);
    } else if (whence == seek_end) {
        position = rb_funcall(UB4_TO_NUM(oci8_lob_get_length(lob)), id_plus, 1, position);
    }
    lob->pos = NUM2UINT(position);
    return self;
}

/*
 *  Sets the current offset at the beginning.
 *
 *  @return [true or false]
 */
static VALUE oci8_lob_rewind(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    lob->pos = 0;
    return self;
}

/*
 *  call-seq:
 *    truncate(length)
 *
 *  Changes the lob size to the given <i>length</i>.
 *
 *  @param [Integer] length
 *  @return [self]
 */
static VALUE oci8_lob_truncate(VALUE self, VALUE len)
{
    oci8_lob_t *lob = DATA_PTR(self);
    oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);

    lob_open(lob);
    chker2(OCILobTrim_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, NUM2UINT(len)),
           &svcctx->base);
    return self;
}

/*
 *  call-seq:
 *    size = length
 *
 *  Changes the lob size to the given <i>length</i>.
 *
 *  @param [Integer] length
 *  @return [Integer]
 */
static VALUE oci8_lob_set_size(VALUE self, VALUE len)
{
    oci8_lob_truncate(self, len);
    return len;
}

/*
 *  call-seq:
 *    read(length = nil)
 *
 *  Reads <i>length</i> characters for CLOB and NCLOB or <i>length</i>
 *  bytes for BLOB and BILF from the current position.
 *  If <i>length</i> is <code>nil</code>, it reads data until EOF.
 *
 *  It returns a string or <code>nil</code>. <code>nil</code> means it
 *  met EOF at beginning. As a special exception, when <i>length</i> is
 *  <code>nil</code> and the lob length is zero, it returns an empty string ''.
 *
 *  @param [Integer] length
 *  @return [String or nil]
 */
static VALUE oci8_lob_read(int argc, VALUE *argv, VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);
    ub4 length;
    ub4 nchar;
    ub4 amt;
    sword rv;
    char buf[8192];
    size_t buf_size_in_char;
    VALUE size;
    VALUE v = rb_ary_new();

    rb_scan_args(argc, argv, "01", &size);
    length = oci8_lob_get_length(lob);
    if (length == 0 && NIL_P(size)) {
        return rb_usascii_str_new("", 0);
    }
    if (length <= lob->pos) /* EOF */
        return Qnil;
    length -= lob->pos;
    if (NIL_P(size)) {
        nchar = length; /* read until EOF */
    } else {
        nchar = NUM2UINT(size);
        if (nchar > length)
            nchar = length;
    }
    amt = nchar;
    buf_size_in_char = sizeof(buf) / lob->char_width;
    do {
        if (lob->state == S_BFILE_CLOSE) {
            rv = OCILobFileOpen_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, OCI_FILE_READONLY);
            if (rv == OCI_ERROR && oci8_get_error_code(oci8_errhp) == 22290) {
                /* ORA-22290: operation would exceed the maximum number of opened files or LOBs */
                /* close all opened BFILE implicitly. */
                oci8_base_t *base;
                for (base = &lob->base; base != &lob->base; base = base->next) {
                    if (base->type == OCI_DTYPE_LOB) {
                        oci8_lob_t *tmp = (oci8_lob_t *)base;
                        if (tmp->state == S_BFILE_OPEN) {
                            tmp->state = S_BFILE_CLOSE;
                        }
                    }
                }
                chker2(OCILobFileCloseAll_nb(svcctx, svcctx->base.hp.svc, oci8_errhp),
                       &svcctx->base);
                continue;
            }
            chker2(rv, &svcctx->base);
            lob->state = S_BFILE_OPEN;
        }
        /* initialize buf in zeros everytime to check a nul characters. */
        memset(buf, 0, sizeof(buf));
        rv = OCILobRead_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, &amt, lob->pos + 1, buf, sizeof(buf), NULL, NULL, 0, lob->csfrm);
        svcctx->suppress_free_temp_lobs = 0;
        switch (rv) {
        case OCI_SUCCESS:
            break;
        case OCI_NEED_DATA:
            /* prevent OCILobFreeTemporary() from being called.
             * See: https://github.com/kubo/ruby-oci8/issues/20
             */
            svcctx->suppress_free_temp_lobs = 1;
            break;
        case OCI_ERROR:
            if (oci8_get_error_code(oci8_errhp) == 22289) {
                /* ORA-22289: cannot perform FILEREAD operation on an unopened file or LOB */
                if (lob->state == S_BFILE_CLOSE)
                    continue;
            }
            /* FALLTHROUGH */
        default:
            chker2(rv, &svcctx->base);
        }

        /* Workaround when using Oracle 10.2.0.4 or 11.1.0.6 client and
         * variable-length character set (e.g. AL32UTF8).
         *
         * When the above mentioned condition, amt may be shorter. So
         * amt is increaded until a nul character to know the actually
         * read size.
         */
        while (amt < sizeof(buf) && buf[amt] != '\0') {
            amt++;
        }

        if (amt == 0)
            break;
        /* for fixed size charset, amt is the number of characters stored in buf. */
        if (amt > buf_size_in_char)
            rb_raise(eOCIException, "Too large buffer fetched or you set too large size of a character.");
        amt *= lob->char_width;
        rb_ary_push(v, rb_str_new(buf, amt));
    } while (rv == OCI_NEED_DATA);
    lob->pos += nchar;
    if (nchar == length) {
        lob_close(lob);
        bfile_close(lob);
    }
    if (RARRAY_LEN(v) == 0) {
        return Qnil;
    }
    v = rb_ary_join(v, Qnil);
    OBJ_TAINT(v);
    if (lob->lobtype == OCI_TEMP_CLOB) {
        /* set encoding */
        rb_enc_associate(v, oci8_encoding);
        return rb_str_conv_enc(v, oci8_encoding, rb_default_internal_encoding());
    } else {
        /* ASCII-8BIT */
        return v;
    }
}

/*
 *  call-seq:
 *    write(data)
 *
 *  Writes <i>data</i>.
 *
 *  @param [String] data
 *  @return [Integer]
 */
static VALUE oci8_lob_write(VALUE self, VALUE data)
{
    oci8_lob_t *lob = DATA_PTR(self);
    oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);
    ub4 amt;

    lob_open(lob);
    if (TYPE(data) != T_STRING) {
        data = rb_obj_as_string(data);
    }
    if (lob->lobtype == OCI_TEMP_CLOB) {
        data = rb_str_export_to_enc(data, oci8_encoding);
    }
    RB_GC_GUARD(data);
    amt = RSTRING_LEN(data);
    if (amt == 0) {
        /* to avoid ORA-24801: illegal parameter value in OCI lob function */
        return INT2FIX(0);
    }
    chker2(OCILobWrite_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, &amt, lob->pos + 1, RSTRING_PTR(data), amt, OCI_ONE_PIECE, NULL, NULL, 0, lob->csfrm),
           &svcctx->base);
    lob->pos += amt;
    return UINT2NUM(amt);
}

/*
 *  @deprecated I'm not sure that this is what the name indicates.
 *  @private
 */
static VALUE oci8_lob_get_sync(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    return (lob->state == S_NO_OPEN_CLOSE) ? Qtrue : Qfalse;
}

/*
 *  @deprecated I'm not sure that this is what the name indicates.
 *  @private
 */
static VALUE oci8_lob_set_sync(VALUE self, VALUE b)
{
    oci8_lob_t *lob = DATA_PTR(self);
    if (RTEST(b)) {
        lob_close(lob);
        lob->state = S_NO_OPEN_CLOSE;
    } else {
        if (lob->state == S_NO_OPEN_CLOSE)
            lob->state = S_CLOSE;
    }
    return b;
}

/*
 *  @deprecated I'm not sure that this is what the name indicates.
 *  @private
 */
static VALUE oci8_lob_flush(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    lob_close(lob);
    return self;
}

/*
 *  Returns the chunk size of a LOB.
 *
 *  @see http://docs.oracle.com/cd/E16338_01/appdev.112/e10646/oci17msc002.htm#i493090
 *  @return [Integer]
 */
static VALUE oci8_lob_get_chunk_size(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);
    ub4 len;

    chker2(OCILobGetChunkSize_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, &len),
           &svcctx->base);
    return UINT2NUM(len);
}

static VALUE oci8_lob_clone(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    oci8_lob_t *newlob;
    VALUE newobj;
    boolean is_temporary;

    newobj = rb_funcall(CLASS_OF(self), oci8_id_new, 1, lob->svc);
    newlob = DATA_PTR(newobj);
    if (OCILobIsTemporary(oci8_envhp, oci8_errhp, lob->base.hp.lob, &is_temporary) == OCI_SUCCESS
        && is_temporary) {
        oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);
        chker2(OCILobLocatorAssign_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, &newlob->base.hp.lob),
               &svcctx->base);
    } else {
        chker2(OCILobAssign(oci8_envhp, oci8_errhp, lob->base.hp.lob, &newlob->base.hp.lob), &lob->base);
    }
    return newobj;
}

static void oci8_bfile_get_name(VALUE self, VALUE *dir_alias_p, VALUE *filename_p)
{
    int need_get = 0;
    if (dir_alias_p != NULL) {
        *dir_alias_p = rb_ivar_get(self, id_dir_alias);
        if (NIL_P(*dir_alias_p))
            need_get = 1;
    }
    if (filename_p != NULL) {
        *filename_p = rb_ivar_get(self, id_filename);
        if (NIL_P(*filename_p))
            need_get = 1;
    }
    if (need_get) {
        oci8_lob_t *lob = DATA_PTR(self);
        char d_buf[31];
        ub2 d_length = sizeof(d_buf);
        char f_buf[256];
        ub2 f_length = sizeof(f_buf);
        VALUE dir_alias;
        VALUE filename;

        chker2(OCILobFileGetName(oci8_envhp, oci8_errhp, lob->base.hp.lob, TO_ORATEXT(d_buf), &d_length, TO_ORATEXT(f_buf), &f_length),
               &lob->base);
        dir_alias = rb_external_str_new_with_enc(d_buf, d_length, oci8_encoding);
        filename = rb_external_str_new_with_enc(f_buf, f_length, oci8_encoding);
        rb_ivar_set(self, id_dir_alias, dir_alias);
        rb_ivar_set(self, id_filename, filename);
        if (dir_alias_p != NULL) {
            *dir_alias_p = dir_alias;
        }
        if (filename_p != NULL) {
            *filename_p = filename;
        }
    }
}

static void oci8_bfile_set_name(VALUE self, VALUE dir_alias, VALUE filename)
{
    oci8_lob_t *lob = DATA_PTR(self);

    bfile_close(lob);
    if (RSTRING_LEN(dir_alias) > UB2MAXVAL) {
        rb_raise(rb_eRuntimeError, "dir_alias is too long.");
    }
    if (RSTRING_LEN(filename) > UB2MAXVAL) {
        rb_raise(rb_eRuntimeError, "filename is too long.");
    }
    chker2(OCILobFileSetName(oci8_envhp, oci8_errhp, &lob->base.hp.lob,
                             RSTRING_ORATEXT(dir_alias), (ub2)RSTRING_LEN(dir_alias),
                             RSTRING_ORATEXT(filename), (ub2)RSTRING_LEN(filename)),
           &lob->base);
}

/*
 *  call-seq:
 *    initialize(conn, dir_alias = nil, filename = nil)
 *
 *  Creates a BFILE object.
 *  This is correspond to {http://docs.oracle.com/cd/E11882_01/server.112/e17118/functions019.htm#sthref953 BFILENAME}.
 *
 *  @param [OCI8] conn
 *  @param [String] dir_alias  a directory object created by
 *    {http://docs.oracle.com/cd/E11882_01/server.112/e17118/statements_5007.htm "CREATE DIRECTORY"}.
 *  @param [String] filename
 *  @return [OCI8::BFILE]
 */
static VALUE oci8_bfile_initialize(int argc, VALUE *argv, VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    VALUE svc;
    VALUE dir_alias;
    VALUE filename;
    int rv;

    rb_scan_args(argc, argv, "12", &svc, &dir_alias, &filename);
    TO_SVCCTX(svc); /* check argument type */
    rv = OCIDescriptorAlloc(oci8_envhp, &lob->base.hp.ptr, OCI_DTYPE_LOB, 0, NULL);
    if (rv != OCI_SUCCESS) {
        oci8_env_raise(oci8_envhp, rv);
    }
    lob->base.type = OCI_DTYPE_LOB;
    lob->svc = svc;
    lob->pos = 0;
    lob->char_width = 1;
    lob->csfrm = SQLCS_IMPLICIT;
    lob->lobtype = OCI_TEMP_BLOB;
    lob->state = S_BFILE_CLOSE;
    if (argc != 1) {
        OCI8SafeStringValue(dir_alias);
        OCI8SafeStringValue(filename);
        oci8_bfile_set_name(self, dir_alias, filename);
    }
    oci8_link_to_parent((oci8_base_t*)lob, (oci8_base_t*)DATA_PTR(svc));
    return Qnil;
}

/*
 *  Returns the directory object name.
 *
 *  @return [String]
 */
static VALUE oci8_bfile_get_dir_alias(VALUE self)
{
    VALUE dir_alias;

    oci8_bfile_get_name(self, &dir_alias, NULL);
    return dir_alias;
}

/*
 *  Returns the file name.
 *
 *  @return [String]
 */
static VALUE oci8_bfile_get_filename(VALUE self)
{
    VALUE filename;

    oci8_bfile_get_name(self, NULL, &filename);
    return filename;
}

/*
 *  call-seq:
 *    dir_alias = name
 *
 *  Changes the directory object name.
 *
 *  @param [String] name
 */
static VALUE oci8_bfile_set_dir_alias(VALUE self, VALUE dir_alias)
{
    VALUE filename;

    OCI8SafeStringValue(dir_alias);
    oci8_bfile_get_name(self, NULL, &filename);
    oci8_bfile_set_name(self, dir_alias, filename);
    rb_ivar_set(self, id_dir_alias, dir_alias);
    return dir_alias;
}

/*
 *  call-seq:
 *    filename = name
 *
 *  Changes the file name.
 *
 *  @param [String] name
 */
static VALUE oci8_bfile_set_filename(VALUE self, VALUE filename)
{
    VALUE dir_alias;

    OCI8SafeStringValue(filename);
    oci8_bfile_get_name(self, &dir_alias, NULL);
    oci8_bfile_set_name(self, dir_alias, filename);
    rb_ivar_set(self, id_filename, filename);
    return filename;
}

/*
 *  Returns <code>true</code> when the BFILE exists on the server's operating system.
 *
 *  @return [true or false]
 */
static VALUE oci8_bfile_exists_p(VALUE self)
{
    oci8_lob_t *lob = DATA_PTR(self);
    oci8_svcctx_t *svcctx = oci8_get_svcctx(lob->svc);
    boolean flag;

    chker2(OCILobFileExists_nb(svcctx, svcctx->base.hp.svc, oci8_errhp, lob->base.hp.lob, &flag),
           &svcctx->base);
    return flag ? Qtrue : Qfalse;
}

/*
 *  Document-method: OCI8::BFILE#truncate
 *
 *  call-seq:
 *    truncate(length)
 *
 *  Raises <code>RuntimeError</code>.
 *
 *  @raise [RuntimeError] cannot modify a read-only BFILE object
 */

/*
 *  Document-method: OCI8::BFILE#size=
 *
 *  call-seq:
 *    size = length
 *
 *  Raises <code>RuntimeError</code>.
 *
 *  @raise [RuntimeError] cannot modify a read-only BFILE object
 */

/*
 *  Document-method: OCI8::BFILE#write
 *
 *  call-seq:
 *    write(data)
 *
 *  Raises <code>RuntimeError</code>.
 *
 *  @raise [RuntimeError] cannot modify a read-only BFILE object
 */

static VALUE oci8_bfile_error(VALUE self, VALUE dummy)
{
    rb_raise(rb_eRuntimeError, "cannot modify a read-only BFILE object");
}

/*
 * bind_clob/blob/bfile
 */

typedef struct {
    oci8_bind_vtable_t bind;
    VALUE *klass;
} oci8_bind_lob_vtable_t;

static VALUE bind_lob_get(oci8_bind_t *obind, void *data, void *null_struct)
{
    oci8_hp_obj_t *oho = (oci8_hp_obj_t *)data;
    return oci8_lob_clone(oho->obj);
}

static void bind_lob_set(oci8_bind_t *obind, void *data, void **null_structp, VALUE val)
{
    oci8_hp_obj_t *oho = (oci8_hp_obj_t *)data;
    const oci8_bind_lob_vtable_t *vptr = (const oci8_bind_lob_vtable_t *)obind->base.vptr;
    oci8_base_t *h;
    if (!rb_obj_is_kind_of(val, *vptr->klass))
        rb_raise(rb_eArgError, "Invalid argument: %s (expect %s)", rb_class2name(CLASS_OF(val)), rb_class2name(*vptr->klass));
    h = DATA_PTR(val);
    oho->hp = h->hp.ptr;
    oho->obj = val;
}

static void bind_lob_init(oci8_bind_t *obind, VALUE svc, VALUE val, VALUE length)
{
    obind->value_sz = sizeof(void *);
    obind->alloc_sz = sizeof(oci8_hp_obj_t);
}

static void bind_lob_init_elem(oci8_bind_t *obind, VALUE svc)
{
    const oci8_bind_lob_vtable_t *vptr = (const oci8_bind_lob_vtable_t *)obind->base.vptr;
    oci8_hp_obj_t *oho = (oci8_hp_obj_t *)obind->valuep;
    oci8_base_t *h;
    ub4 idx = 0;

    do {
        oho[idx].obj = rb_funcall(*vptr->klass, oci8_id_new, 1, svc);
        h = DATA_PTR(oho[idx].obj);
        oho[idx].hp = h->hp.ptr;
    } while (++idx < obind->maxar_sz);
}

static void bind_lob_post_bind_hook_for_nclob(oci8_bind_t *obind)
{
    ub1 csfrm = SQLCS_NCHAR;

    chker2(OCIAttrSet(obind->base.hp.ptr, obind->base.type, (void*)&csfrm, 0, OCI_ATTR_CHARSET_FORM, oci8_errhp),
           &obind->base);
}

static const oci8_bind_lob_vtable_t bind_clob_vtable = {
    {
        {
            oci8_bind_hp_obj_mark,
            oci8_bind_free,
            sizeof(oci8_bind_t)
        },
        bind_lob_get,
        bind_lob_set,
        bind_lob_init,
        bind_lob_init_elem,
        NULL,
        SQLT_CLOB
    },
    &cOCI8CLOB
};

static const oci8_bind_lob_vtable_t bind_nclob_vtable = {
    {
        {
            oci8_bind_hp_obj_mark,
            oci8_bind_free,
            sizeof(oci8_bind_t)
        },
        bind_lob_get,
        bind_lob_set,
        bind_lob_init,
        bind_lob_init_elem,
        NULL,
        SQLT_CLOB,
        bind_lob_post_bind_hook_for_nclob,
    },
    &cOCI8NCLOB
};

static const oci8_bind_lob_vtable_t bind_blob_vtable = {
    {
        {
            oci8_bind_hp_obj_mark,
            oci8_bind_free,
            sizeof(oci8_bind_t)
        },
        bind_lob_get,
        bind_lob_set,
        bind_lob_init,
        bind_lob_init_elem,
        NULL,
        SQLT_BLOB
    },
    &cOCI8BLOB
};

static const oci8_bind_lob_vtable_t bind_bfile_vtable = {
    {
        {
            oci8_bind_hp_obj_mark,
            oci8_bind_free,
            sizeof(oci8_bind_t)
        },
        bind_lob_get,
        bind_lob_set,
        bind_lob_init,
        bind_lob_init_elem,
        NULL,
        SQLT_BFILE
    },
    &cOCI8BFILE
};

void Init_oci8_lob(VALUE cOCI8)
{
    id_plus = rb_intern("+");
    id_dir_alias = rb_intern("@dir_alias");
    id_filename = rb_intern("@filename");
    seek_set = rb_eval_string("::IO::SEEK_SET");
    seek_cur = rb_eval_string("::IO::SEEK_CUR");
    seek_end = rb_eval_string("::IO::SEEK_END");

#if 0
    cOCIHandle = rb_define_class("OCIHandle", rb_cObject);
    cOCI8 = rb_define_class("OCI8", cOCIHandle);
    cOCI8LOB = rb_define_class_under(cOCI8, "LOB", cOCIHandle);
#endif

    cOCI8LOB = oci8_define_class_under(cOCI8, "LOB", &oci8_lob_vtable);
    cOCI8CLOB = rb_define_class_under(cOCI8, "CLOB", cOCI8LOB);
    cOCI8NCLOB = rb_define_class_under(cOCI8, "NCLOB", cOCI8LOB);
    cOCI8BLOB = rb_define_class_under(cOCI8, "BLOB", cOCI8LOB);
    cOCI8BFILE = rb_define_class_under(cOCI8, "BFILE", cOCI8LOB);

    rb_define_method(cOCI8CLOB, "initialize", oci8_clob_initialize, -1);
    rb_define_method(cOCI8NCLOB, "initialize", oci8_nclob_initialize, -1);
    rb_define_method(cOCI8BLOB, "initialize", oci8_blob_initialize, -1);
    rb_define_private_method(cOCI8LOB, "__char_width=", oci8_lob_set_char_width, 1);
    rb_define_method(cOCI8LOB, "available?", oci8_lob_available_p, 0);
    rb_define_method(cOCI8LOB, "size", oci8_lob_get_size, 0);
    rb_define_method(cOCI8LOB, "pos", oci8_lob_get_pos, 0);
    rb_define_alias(cOCI8LOB, "tell", "pos");
    rb_define_method(cOCI8LOB, "eof?", oci8_lob_eof_p, 0);
    rb_define_method(cOCI8LOB, "seek", oci8_lob_seek, -1);
    rb_define_method(cOCI8LOB, "rewind", oci8_lob_rewind, 0);
    rb_define_method(cOCI8LOB, "truncate", oci8_lob_truncate, 1);
    rb_define_method(cOCI8LOB, "size=", oci8_lob_set_size, 1);
    rb_define_method(cOCI8LOB, "read", oci8_lob_read, -1);
    rb_define_method(cOCI8LOB, "write", oci8_lob_write, 1);
    rb_define_method(cOCI8LOB, "close", oci8_lob_close, 0);
    rb_define_method(cOCI8LOB, "sync", oci8_lob_get_sync, 0);
    rb_define_method(cOCI8LOB, "sync=", oci8_lob_set_sync, 1);
    rb_define_method(cOCI8LOB, "flush", oci8_lob_flush, 0);
    rb_define_method(cOCI8LOB, "chunk_size", oci8_lob_get_chunk_size, 0);

    rb_define_method(cOCI8BFILE, "initialize", oci8_bfile_initialize, -1);
    rb_define_method(cOCI8BFILE, "dir_alias", oci8_bfile_get_dir_alias, 0);
    rb_define_method(cOCI8BFILE, "filename", oci8_bfile_get_filename, 0);
    rb_define_method(cOCI8BFILE, "dir_alias=", oci8_bfile_set_dir_alias, 1);
    rb_define_method(cOCI8BFILE, "filename=", oci8_bfile_set_filename, 1);
    rb_define_method(cOCI8BFILE, "exists?", oci8_bfile_exists_p, 0);
    rb_define_method(cOCI8BFILE, "truncate", oci8_bfile_error, 1);
    rb_define_method(cOCI8BFILE, "size=", oci8_bfile_error, 1);
    rb_define_method(cOCI8BFILE, "write", oci8_bfile_error, 1);

    oci8_define_bind_class("CLOB", &bind_clob_vtable.bind);
    oci8_define_bind_class("NCLOB", &bind_nclob_vtable.bind);
    oci8_define_bind_class("BLOB", &bind_blob_vtable.bind);
    oci8_define_bind_class("BFILE", &bind_bfile_vtable.bind);
}