Pollen
"""
Server(project, builder)
A server manages interactively running a `Project`, coordinating events
to update project state efficiently.
"""
mutable
struct
Server
project
::
Any
builder
::
Any
updates
::
Any
lock
::
Any
end
function
Server
(
project
,
builder
=
FileBuilder
(
HTMLFormat
(
)
,
Path
(
mktempdir
(
)
)
)
)
Server
(
project
,
builder
,
Updates
(
)
,
ReentrantLock
(
)
)
end
"""
abstract type ServerMode
Mode that a `Server` can run in. Controls how events affect the project
state.
"""
abstract
type
ServerMode
end
geteventhandler
(
::
ServerMode
,
server
,
ch
)
=
nothing
handle
(
_
,
::
ServerMode
,
::
Event
)
=
return
initialize
(
::
ServerMode
,
server
)
=
return
"""
handle(server, mode, event)
handle(rewriter, event)
"""
function
handle
end
"""
runserver(server, mode)
Run a `server` in `mode`. Handles start and cleanup of event sources
from rewriters and `mode`. Synchronizes updates to project state.
"""
function
runserver
(
server
,
mode
;
dt
=
1
/
60
)
eventch
=
Channel
(
)
eventhandlers
=
servereventhandlers
(
server
,
mode
,
eventch
)
initialize
(
mode
,
server
)
@
async
begin
for
event
in
eventch
@
debug
"
Received
$
(
typeof
(
event
)
)
"
event
=
event
try
handle
(
server
,
mode
,
event
)
foreach
(
r
->
handle
(
r
,
event
)
,
eventhandlers
)
catch
e
@
error
"
Error was thrown during handling of event!
"
event
=
event
error
=
e
end
end
end
tasks
=
nothing
try
tasks
=
map
(
startasync
,
eventhandlers
)
@
info
"
Starting server...
"
while
true
updates
=
server
.
updates
lock
(
server
.
lock
)
do
server
.
updates
=
Updates
(
)
end
_
,
events
=
applyupdates!
(
server
.
project
,
server
.
builder
,
updates
)
foreach
(
e
->
put!
(
eventch
,
e
)
,
events
)
if
!
all
(
isempty
.
(
(
updates
.
sources
,
updates
.
torewrite
,
updates
.
torebuild
)
)
)
@
info
"
Rebuild complete.
"
end
sleep
(
dt
)
end
catch
e
if
e
isa
InterruptException
@
info
"
Shutting down server...
"
else
rethrow
(
e
)
end
finally
isnothing
(
tasks
)
||
foreach
(
stopasync
,
eventhandlers
,
tasks
)
close
(
eventch
)
end
end
Updates is a container that asynchronously collects updates to the project state which are then applied synchronously. For example, a file watcher can update source documents using
addsource! and trigger rewrites and builds using
addrewrite! and [
addbuild!]. Only in
applyupdates! are the changes actually applied to a project.
"""
struct Updates
Tracks updates to project state. Used internally by [`runserver`](#).
"""
struct
Updates
sources
::
Any
torewrite
::
Any
torebuild
::
Any
end
Updates
(
)
=
Updates
(
Dict
{
String
,
Node
}
(
)
,
Set
{
String
}
(
)
,
Set
{
String
}
(
)
)
"""
applyupdates!(project, builder, updates::Updates)
Apply `updates` to a project by updating sources, rewriting and building
documents.
"""
function
applyupdates!
(
project
,
builder
,
updates
::
Updates
)
events
=
Event
[
]
for
(
p
,
doc
)
in
updates
.
sources
project
.
sources
[
p
]
=
doc
end
dirtypaths
=
if
!
isempty
(
updates
.
torewrite
)
rewritesources!
(
project
,
updates
.
torewrite
)
else
Set
(
)
end
dirtypaths
=
union
(
dirtypaths
,
updates
.
torebuild
)
if
!
isempty
(
dirtypaths
)
build
(
builder
,
project
,
dirtypaths
)
for
p
in
dirtypaths
push!
(
events
,
DocRebuilt
(
p
)
)
end
end
return
project
,
events
end
function
applyupdates!
(
server
::
Server
)
applyupdates!
(
server
.
project
,
server
.
builder
,
server
.
updates
)
end
function
addsource!
(
server
,
docid
,
doc
)
lock
(
server
.
lock
)
do
server
.
updates
.
sources
[
docid
]
=
doc
end
end
function
addrewrite!
(
server
,
docid
)
lock
(
server
.
lock
)
do
if
haskey
(
server
.
project
.
sources
,
docid
)
||
haskey
(
server
.
updates
.
sources
,
path
)
push!
(
server
.
updates
.
torewrite
,
docid
)
else
@
warn
"
Cannot find source document
$
docid
to rewrite!
"
error
(
"
Cannot find source document
$
docid
to rewrite!
"
)
end
end
end
function
addbuild!
(
server
,
docid
)
lock
(
server
.
lock
)
do
if
haskey
(
server
.
project
.
outputs
,
docid
)
||
docid
in
server
.
updates
.
torewrite
push!
(
server
.
updates
.
torebuild
,
docid
)
else
error
(
"
Cannot find output document
$
docid
to build!
"
)
end
end
end
function
servereventhandlers
(
server
,
mode
,
ch
)
eventhandlers
=
[
]
for
rewriter
in
server
.
project
.
rewriters
eventhandler
=
geteventhandler
(
rewriter
,
ch
)
isnothing
(
eventhandler
)
||
push!
(
eventhandlers
,
eventhandler
)
end
eventhandler
=
geteventhandler
(
mode
,
server
,
ch
)
isnothing
(
eventhandler
)
||
push!
(
eventhandlers
,
eventhandler
)
return
eventhandlers
end