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8.5.3.2 Engine Support
The most significant changes to engine support components are the support of Unicode, the
application architecture’s support of non-EPOC documents identified by MIME type, the client-
server implementation of the DBMS, and multiple process support in the C Standard Library.
8.5.3.2.1 Unicode support
The resource compiler now supports source files in a variety of code pages (including Shift-JIS),
and generated resource files in 8-bit or Unicode character sets. However, the resource compiler’s
output generates only 8-bit characters, with high bits padded to 0x00.
A new front-end processor (FEP) architecture, represented by the FEPBASE component, allows
entry using methods other than standard keyboard and CONE controls — without changing
existing application code.
A broadcast server, BRDCST, has been designed to send FEP-related messages to client
applications.
ETEXT supports entry using front-end processors.
CHARCONV is a new component which supports character conversions between code pages,
with sufficient generality for Unicode requirements.
In Unicode builds, the server side of LEXICON is essentially unchanged, since spell checks are
only supported for alphabetical languages. The client side has been changed to convert 16-bit
characters down to 8-bit for handling by the server.
8.5.3.2.2 Application Architecture
In EPOC R3, the application architecture can only launch a document if it is of a recognized
EPOC file format. This format relies on recognition by UID and a stream-store-based data
structure, which allows for lean-and-mean embedded objects. In EPOC R5, document embedding
is still supported and requires native EPOC file formats.
In EPOC R3, non-EPOC files (such as plain text) had to be imported into a running EPOC
application, by a
File | More | Import menu item. In EPOC R5, non-EPOC files can be
recognized by the application architecture, and associated with one or more MIME types, which
are in turn used to associate an application with the file format.
A converter architecture has also been added to provide for conversion between native and non-
native formats. A library of standard converters is also provided, including
• ASCII text to ETEXT internal representation and back
• MIME quoted-printable encoding and decoding
• base-64 encoding and decoding
• plain text to embeddable EPOC Word document stream and back
aiftool has been modified to allow the mappings between file formats and applications to be
specified. APPARC has been modified to provide the relevant support. New components
CONARC and EMIME provide the basic framework for converters and MIME type recognition.
The application architecture server encapsulates the programming interfaces and should now be
used to broker all application launching — whether by the EPOC Shell, by the GUI launching
embedded objects, or by applications such as e-mail and web clients launching other documents.
8.5.3.2.3 DBMS
DBMS has many improvements. The client API has been enhanced, in an backward binary
compatible manner.
The most significant enhancement is a new DBMS server which can own databases on behalf of
multiple clients, thereby enabling well-controlled sharing while the database is open.
A new database factory provides the ability to open a database by name: either for fast, exclusive,
client-side access or for sharing with other programs using the server. The former is much like the
earlier store-database but without direct access to the store object, while the latter supports
transaction locking, and a notification interface indicating when (for instance) locks have been
released.
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