'filecache' .urp directive, fixing a longstanding MonoUtil bug in the process

1 files changed, 1 insertions, 0 deletions

diff --git a/doc/manual.tex b/doc/manual.tex
index 985dab5b..857539db 100644
--- a/doc/manual.tex
+++ b/doc/manual.tex
@@ -151,6 +151,7 @@ Here is the complete list of directive forms.  ``FFI'' stands for ``foreign func
 \item \texttt{exe FILENAME} sets the filename to which to write the output executable.  The default for file \texttt{P.urp} is \texttt{P.exe}.
 \item \texttt{file URI FILENAME} asks for the application executable to respond to requests for \texttt{URI} by serving a snapshot of the contents of \texttt{FILENAME} as of compile time.  That is, the file contents are baked into the executable.  System file \texttt{/etc/mime.types} is consulted (again, at compile time) to figure out the right MIME type to suggest in the HTTP response.
 \item \texttt{file URI FILENAME MIME-TYPE} works like the simpler form of \texttt{file}, but the proper MIME type for the file is given directly.
+\item \texttt{filecache PATH} sets a path to a directory to use for caching files stored in the SQL database.  It can be expensive to schlep files back and forth between the database and an Ur/Web application, since database engines don't tend to be optimized for transferring large files.  Ur/Web will still store the files in the database, as the ``version of record'' for your whole, consistent data set, but the application will try to query the database only in terms of cryptographic hashes, from which files can be retrieved from the cache.  (This feature is currently only available for PostgreSQL, with the module \texttt{pgcrypto} installed, to drive SHA512 hashing.  It would defeat the purpose to run the hashing operation in the application rather than the database engine!)
 \item \texttt{ffi FILENAME} reads the file \texttt{FILENAME.urs} to determine the interface to a new FFI module.  The name of the module is calculated from \texttt{FILENAME} in the same way as for normal source files.  See the files \texttt{include/urweb/urweb\_cpp.h} and \texttt{src/c/urweb.c} for examples of C headers and implementations for FFI modules.  In general, every type or value \texttt{Module.ident} becomes \texttt{uw\_Module\_ident} in C.
 \item \texttt{html5} asks to generate HTML5 code, which primarily affects the first few lines of the output documents, like the \texttt{DOCTYPE}.  This option is on by default.
 \item \texttt{include FILENAME} adds \texttt{FILENAME} to the list of files to be \texttt{\#include}d in C sources.  This is most useful for interfacing with new FFI modules.