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riak_kv_wm_object.erl
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riak_kv_wm_object.erl
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%% -------------------------------------------------------------------
%%
%% riak_kv_wm_object: Webmachine resource for KV object level operations.
%%
%% Copyright (c) 2007-2011 Basho Technologies, Inc. All Rights Reserved.
%%
%% This file is provided to you under the Apache License,
%% Version 2.0 (the "License"); you may not use this file
%% except in compliance with the License. You may obtain
%% a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing,
%% software distributed under the License is distributed on an
%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
%% KIND, either express or implied. See the License for the
%% specific language governing permissions and limitations
%% under the License.
%%
%% -------------------------------------------------------------------
%% @doc Resource for serving Riak objects over HTTP.
%%
%% Available operations:
%%
%% POST /buckets/Bucket/keys (NEW)
%% POST /Prefix/Bucket (OLD)
%% Equivalent to "PUT /Prefix/Bucket/Key" where Key is chosen
%% by the server.
%%
%% GET /buckets/Bucket/keys/Key (NEW)
%% GET /Prefix/Bucket/Key (OLD)
%% Get the data stored in the named Bucket under the named Key.
%% Content-type of the response will be whatever incoming
%% Content-type was used in the request that stored the data.
%% Additional headers will include:
%% X-Riak-Vclock: The vclock of the object.
%% Link: The links the object has
%% Etag: The Riak "vtag" metadata of the object
%% Last-Modified: The last-modified time of the object
%% Encoding: The value of the incoming Encoding header from
%% the request that stored the data.
%% X-Riak-Meta-: Any headers prefixed by X-Riak-Meta- supplied
%% on PUT are returned verbatim
%% Specifying the query param "r=R", where R is an integer will
%% cause Riak to use R as the r-value for the read request. A
%% default r-value of 2 will be used if none is specified.
%% If the object is found to have siblings (only possible if the
%% bucket property "allow_mult" has been set to true), then
%% Content-type will be text/plain; Link, Etag, and Last-Modified
%% headers will be omitted; and the body of the response will
%% be a list of the vtags of each sibling. To request a specific
%% sibling, include the query param "vtag=V", where V is the vtag
%% of the sibling you want.
%%
%% PUT /buckets/Bucket/keys/Key (NEW)
%% PUT /Prefix/Bucket/Key (OLD)
%% Store new data in the named Bucket under the named Key.
%% A Content-type header *must* be included in the request. The
%% value of this header will be used in the response to subsequent
%% GET requests.
%% The body of the request will be stored literally as the value
%% of the riak_object, and will be served literally as the body of
%% the response to subsequent GET requests.
%% Include an X-Riak-Vclock header to modify data without creating
%% siblings.
%% Include a Link header to set the links of the object.
%% Include an Encoding header if you would like an Encoding header
%% to be included in the response to subsequent GET requests.
%% Include custom metadata using headers prefixed with X-Riak-Meta-.
%% They will be returned verbatim on subsequent GET requests.
%% Specifying the query param "w=W", where W is an integer will
%% cause Riak to use W as the w-value for the write request. A
%% default w-value of 2 will be used if none is specified.
%% Specifying the query param "dw=DW", where DW is an integer will
%% cause Riak to use DW as the dw-value for the write request. A
%% default dw-value of 0 will be used if none is specified.
%% Specifying the query param "r=R", where R is an integer will
%% cause Riak to use R as the r-value for the read request (used
%% to determine whether or not the resource exists). A default
%% r-value of 2 will be used if none is specified.
%%
%% POST /buckets/Bucket/keys/Key (NEW)
%% POST /Prefix/Bucket/Key (OLD)
%% Equivalent to "PUT /Prefix/Bucket/Key" (useful for clients that
%% do not support the PUT method).
%%
%% DELETE /buckets/Bucket/keys/Key (NEW)
%% DELETE /Prefix/Bucket/Key (OLD)
%% Delete the data stored in the named Bucket under the named Key.
%% Specifying the query param "rw=RW", where RW is an integer will
%% cause Riak to use RW as the rw-value for the delete request. A
%% default rw-value of 2 will be used if none is specified.
-module(riak_kv_wm_object).
%% webmachine resource exports
-export([
init/1,
service_available/2,
forbidden/2,
allowed_methods/2,
allow_missing_post/2,
malformed_request/2,
resource_exists/2,
last_modified/2,
generate_etag/2,
content_types_provided/2,
charsets_provided/2,
encodings_provided/2,
content_types_accepted/2,
post_is_create/2,
create_path/2,
process_post/2,
produce_doc_body/2,
accept_doc_body/2,
produce_sibling_message_body/2,
produce_multipart_body/2,
multiple_choices/2,
delete_resource/2
]).
%% @type context() = term()
-record(ctx, {api_version, %% integer() - Determine which version of the API to use.
bucket, %% binary() - Bucket name (from uri)
key, %% binary() - Key (from uri)
client, %% riak_client() - the store client
r, %% integer() - r-value for reads
w, %% integer() - w-value for writes
dw, %% integer() - dw-value for writes
rw, %% integer() - rw-value for deletes
pr, %% integer() - number of primary nodes required in preflist on read
pw, %% integer() - number of primary nodes required in preflist on write
basic_quorum, %% boolean() - whether to use basic_quorum
notfound_ok, %% boolean() - whether to treat notfounds as successes
asis, %% boolean() - whether to send the put without modifying the vclock
prefix, %% string() - prefix for resource uris
riak, %% local | {node(), atom()} - params for riak client
doc, %% {ok, riak_object()}|{error, term()} - the object found
vtag, %% string() - vtag the user asked for
bucketprops, %% proplist() - properties of the bucket
links, %% [link()] - links of the object
index_fields, %% [index_field()]
method, %% atom() - HTTP method for the request
timeout %% integer() - passed-in timeout value in ms
}).
%% @type link() = {{Bucket::binary(), Key::binary()}, Tag::binary()}
%% @type index_field() = {Key::string(), Value::string()}
-define(DEFAULT_TIMEOUT, 60000).
-include_lib("webmachine/include/webmachine.hrl").
-include("riak_kv_wm_raw.hrl").
%% @spec init(proplist()) -> {ok, context()}
%% @doc Initialize this resource. This function extracts the
%% 'prefix' and 'riak' properties from the dispatch args.
init(Props) ->
{ok, #ctx{api_version=proplists:get_value(api_version, Props),
prefix=proplists:get_value(prefix, Props),
riak=proplists:get_value(riak, Props)}}.
%% @spec service_available(reqdata(), context()) ->
%% {boolean(), reqdata(), context()}
%% @doc Determine whether or not a connection to Riak
%% can be established. This function also takes this
%% opportunity to extract the 'bucket' and 'key' path
%% bindings from the dispatch, as well as any vtag
%% query parameter.
service_available(RD, Ctx=#ctx{riak=RiakProps}) ->
case riak_kv_wm_utils:get_riak_client(RiakProps, riak_kv_wm_utils:get_client_id(RD)) of
{ok, C} ->
{true,
RD,
Ctx#ctx{
method=wrq:method(RD),
client=C,
bucket=case wrq:path_info(bucket, RD) of
undefined -> undefined;
B -> list_to_binary(riak_kv_wm_utils:maybe_decode_uri(RD, B))
end,
key=case wrq:path_info(key, RD) of
undefined -> undefined;
K -> list_to_binary(riak_kv_wm_utils:maybe_decode_uri(RD, K))
end,
vtag=wrq:get_qs_value(?Q_VTAG, RD)
}};
Error ->
{false,
wrq:set_resp_body(
io_lib:format("Unable to connect to Riak: ~p~n", [Error]),
wrq:set_resp_header(?HEAD_CTYPE, "text/plain", RD)),
Ctx}
end.
forbidden(RD, Ctx) ->
{riak_kv_wm_utils:is_forbidden(RD), RD, Ctx}.
%% @spec allowed_methods(reqdata(), context()) ->
%% {[method()], reqdata(), context()}
%% @doc Get the list of methods this resource supports.
allowed_methods(RD, Ctx) ->
{['HEAD', 'GET', 'POST', 'PUT', 'DELETE'], RD, Ctx}.
%% @spec allow_missing_post(reqdata(), context()) ->
%% {true, reqdata(), context()}
%% @doc Makes POST and PUT equivalent for creating new
%% bucket entries.
allow_missing_post(RD, Ctx) ->
{true, RD, Ctx}.
%% @spec malformed_request(reqdata(), context()) ->
%% {boolean(), reqdata(), context()}
%% @doc Determine whether query parameters, request headers,
%% and request body are badly-formed.
%% Body format is checked to be valid JSON, including
%% a "props" object for a bucket-PUT. Body format
%% is not tested for a key-level request (since the
%% body may be any content the client desires).
%% Query parameters r, w, dw, and rw are checked to
%% be valid integers. Their values are stored in
%% the context() at this time.
%% Link headers are checked for the form:
%% </Prefix/Bucket/Key>; riaktag="Tag",...
%% The parsed links are stored in the context()
%% at this time.
malformed_request(RD, Ctx) when Ctx#ctx.method =:= 'POST'
orelse Ctx#ctx.method =:= 'PUT' ->
malformed_request([fun malformed_content_type/2,
fun malformed_timeout_param/2,
fun malformed_rw_params/2,
fun malformed_link_headers/2,
fun malformed_index_headers/2],
RD, Ctx);
malformed_request(RD, Ctx) ->
malformed_request([fun malformed_timeout_param/2,
fun malformed_rw_params/2,
fun malformed_check_doc/2], RD, Ctx).
%% @doc Given a list of 2-arity funs, threads through the request data
%% and context, returning as soon as a single fun discovers a
%% malformed request or halts.
%% -spec malformed_request([fun()], wrq:reqdata(), #ctx{}) -> {boolean() | {halt, non_neg_integer()}, wrq:reqdata(), #ctx{}}.
malformed_request([], RD, Ctx) ->
{false, RD, Ctx};
malformed_request([H|T], RD, Ctx) ->
case H(RD, Ctx) of
{true, _, _} = Result -> Result;
{{halt,_}, _, _} = Halt -> Halt;
{false, RD1, Ctx1} ->
malformed_request(T, RD1, Ctx1)
end.
%% @doc Detects whether the Content-Type header is missing on
%% PUT/POST.
malformed_content_type(RD, Ctx) ->
case wrq:get_req_header("Content-Type", RD) of
undefined ->
{true, missing_content_type(RD), Ctx};
_ -> {false, RD, Ctx}
end.
%% @doc Detects whether fetching the requested object results in an
%% error.
malformed_check_doc(RD, Ctx) ->
DocCtx = ensure_doc(Ctx),
case DocCtx#ctx.doc of
{error, Reason} ->
handle_common_error(Reason, RD, DocCtx);
_ ->
{false, RD, DocCtx}
end.
%% @spec malformed_timeout_param(reqdata(), context()) ->
%% {boolean(), reqdata(), context()}
%% @doc Check that the timeout parameter is are a
%% string-encoded integer. Store the integer value
%% in context() if so.
malformed_timeout_param(RD, Ctx) ->
case wrq:get_qs_value("timeout", none, RD) of
none ->
{false, RD, Ctx};
TimeoutStr ->
try
Timeout = list_to_integer(TimeoutStr),
{false, RD, Ctx#ctx{timeout=Timeout}}
catch
_:_ ->
{true,
wrq:append_to_resp_body(io_lib:format("Bad timeout "
"value ~p~n",
[TimeoutStr]),
wrq:set_resp_header(?HEAD_CTYPE,
"text/plain", RD)),
Ctx}
end
end.
%% @spec malformed_rw_params(reqdata(), context()) ->
%% {boolean(), reqdata(), context()}
%% @doc Check that r, w, dw, and rw query parameters are
%% string-encoded integers. Store the integer values
%% in context() if so.
malformed_rw_params(RD, Ctx) ->
Res =
lists:foldl(fun malformed_rw_param/2,
{false, RD, Ctx},
[{#ctx.r, "r", "default"},
{#ctx.w, "w", "default"},
{#ctx.dw, "dw", "default"},
{#ctx.rw, "rw", "default"},
{#ctx.pw, "pw", "default"},
{#ctx.pr, "pr", "default"}]),
lists:foldl(fun malformed_boolean_param/2,
Res,
[{#ctx.basic_quorum, "basic_quorum", "default"},
{#ctx.notfound_ok, "notfound_ok", "default"},
{#ctx.asis, "asis", "false"}]).
%% @spec malformed_rw_param({Idx::integer(), Name::string(), Default::string()},
%% {boolean(), reqdata(), context()}) ->
%% {boolean(), reqdata(), context()}
%% @doc Check that a specific r, w, dw, or rw query param is a
%% string-encoded integer. Store its result in context() if it
%% is, or print an error message in reqdata() if it is not.
malformed_rw_param({Idx, Name, Default}, {Result, RD, Ctx}) ->
case catch normalize_rw_param(wrq:get_qs_value(Name, Default, RD)) of
P when (is_atom(P) orelse is_integer(P)) ->
{Result, RD, setelement(Idx, Ctx, P)};
_ ->
{true,
wrq:append_to_resp_body(
io_lib:format("~s query parameter must be an integer or "
"one of the following words: 'one', 'quorum' or 'all'~n",
[Name]),
wrq:set_resp_header(?HEAD_CTYPE, "text/plain", RD)),
Ctx}
end.
%% @spec malformed_boolean_param({Idx::integer(), Name::string(), Default::string()},
%% {boolean(), reqdata(), context()}) ->
%% {boolean(), reqdata(), context()}
%% @doc Check that a specific query param is a
%% string-encoded boolean. Store its result in context() if it
%% is, or print an error message in reqdata() if it is not.
malformed_boolean_param({Idx, Name, Default}, {Result, RD, Ctx}) ->
case string:to_lower(wrq:get_qs_value(Name, Default, RD)) of
"true" ->
{Result, RD, setelement(Idx, Ctx, true)};
"false" ->
{Result, RD, setelement(Idx, Ctx, false)};
"default" ->
{Result, RD, setelement(Idx, Ctx, default)};
_ ->
{true,
wrq:append_to_resp_body(
io_lib:format("~s query parameter must be true or false~n",
[Name]),
wrq:set_resp_header(?HEAD_CTYPE, "text/plain", RD)),
Ctx}
end.
normalize_rw_param("default") -> default;
normalize_rw_param("one") -> one;
normalize_rw_param("quorum") -> quorum;
normalize_rw_param("all") -> all;
normalize_rw_param(V) -> list_to_integer(V).
%% @spec malformed_link_headers(reqdata(), context()) ->
%% {boolean(), reqdata(), context()}
%% @doc Check that the Link header in the request() is valid.
%% Store the parsed links in context() if the header is valid,
%% or print an error in reqdata() if it is not.
%% A link header should be of the form:
%% </Prefix/Bucket/Key>; riaktag="Tag",...
malformed_link_headers(RD, Ctx) ->
case catch get_link_heads(RD, Ctx) of
Links when is_list(Links) ->
{false, RD, Ctx#ctx{links=Links}};
_Error when Ctx#ctx.api_version == 1->
{true,
wrq:append_to_resp_body(
io_lib:format("Invalid Link header. Links must be of the form~n"
"</~s/BUCKET/KEY>; riaktag=\"TAG\"~n",
[Ctx#ctx.prefix]),
wrq:set_resp_header(?HEAD_CTYPE, "text/plain", RD)),
Ctx};
_Error when Ctx#ctx.api_version == 2 ->
{true,
wrq:append_to_resp_body(
io_lib:format("Invalid Link header. Links must be of the form~n"
"</buckets/BUCKET/keys/KEY>; riaktag=\"TAG\"~n", []),
wrq:set_resp_header(?HEAD_CTYPE, "text/plain", RD)),
Ctx}
end.
%% @spec malformed_index_headers(reqdata(), context()) ->
%% {boolean(), reqdata(), context()}
%%
%% @doc Check that the Index headers (HTTP headers prefixed with index_")
%% are valid. Store the parsed headers in context() if valid,
%% or print an error in reqdata() if not.
%% An index field should be of the form "index_fieldname_type"
malformed_index_headers(RD, Ctx) ->
%% Get a list of index_headers...
IndexFields1 = extract_index_fields(RD),
%% Validate the fields. If validation passes, then the index
%% headers are correctly formed.
case riak_index:parse_fields(IndexFields1) of
{ok, IndexFields2} ->
{false, RD, Ctx#ctx { index_fields=IndexFields2 }};
{error, Reasons} ->
{true,
wrq:append_to_resp_body(
[riak_index:format_failure_reason(X) || X <- Reasons],
wrq:set_resp_header(?HEAD_CTYPE, "text/plain", RD)),
Ctx}
end.
%% @spec extract_index_fields(reqdata()) -> proplist().
%%
%% @doc Extract fields from headers prefixed by "x-riak-index-" in the
%% client's PUT request, to be indexed at write time.
extract_index_fields(RD) ->
PrefixSize = length(?HEAD_INDEX_PREFIX),
{ok, RE} = re:compile(",\\s"),
F = fun({K,V}, Acc) ->
KList = riak_kv_wm_utils:any_to_list(K),
case lists:prefix(?HEAD_INDEX_PREFIX, string:to_lower(KList)) of
true ->
%% Isolate the name of the index field.
IndexField = list_to_binary(element(2, lists:split(PrefixSize, KList))),
%% HACK ALERT: Split values on comma. The HTTP
%% spec allows for comma separated tokens
%% where the tokens can be quoted strings. We
%% don't currently support quoted strings.
%% (http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html)
Values = re:split(V, RE, [{return, binary}]),
[{IndexField, X} || X <- Values] ++ Acc;
false ->
Acc
end
end,
lists:foldl(F, [], mochiweb_headers:to_list(wrq:req_headers(RD))).
%% @spec content_types_provided(reqdata(), context()) ->
%% {[{ContentType::string(), Producer::atom()}], reqdata(), context()}
%% @doc List the content types available for representing this resource.
%% The content-type for a key-level request is the content-type that
%% was used in the PUT request that stored the document in Riak.
content_types_provided(RD, Ctx=#ctx{method=Method}=Ctx) when Method =:= 'PUT';
Method =:= 'POST' ->
{ContentType, _} = extract_content_type(RD),
{[{ContentType, produce_doc_body}], RD, Ctx};
content_types_provided(RD, Ctx0) ->
DocCtx = ensure_doc(Ctx0),
%% we can assume DocCtx#ctx.doc is {ok,Doc} because of malformed_request
case select_doc(DocCtx) of
{MD, V} ->
{[{get_ctype(MD,V), produce_doc_body}], RD, DocCtx};
multiple_choices ->
{[{"text/plain", produce_sibling_message_body},
{"multipart/mixed", produce_multipart_body}], RD, DocCtx}
end.
%% @spec charsets_provided(reqdata(), context()) ->
%% {no_charset|[{Charset::string(), Producer::function()}],
%% reqdata(), context()}
%% @doc List the charsets available for representing this resource.
%% The charset for a key-level request is the charset that was used
%% in the PUT request that stored the document in Riak (none if
%% no charset was specified at PUT-time).
charsets_provided(RD, #ctx{method=Method}=Ctx) when Method =:= 'PUT';
Method =:= 'POST' ->
case extract_content_type(RD) of
{_, undefined} ->
{no_charset, RD, Ctx};
{_, Charset} ->
{[{Charset, fun(X) -> X end}], RD, Ctx}
end;
charsets_provided(RD, Ctx0) ->
DocCtx = ensure_doc(Ctx0),
case DocCtx#ctx.doc of
{ok, _} ->
case select_doc(DocCtx) of
{MD, _} ->
case dict:find(?MD_CHARSET, MD) of
{ok, CS} ->
{[{CS, fun(X) -> X end}], RD, DocCtx};
error ->
{no_charset, RD, DocCtx}
end;
multiple_choices ->
{no_charset, RD, DocCtx}
end;
{error, _} ->
{no_charset, RD, DocCtx}
end.
%% @spec encodings_provided(reqdata(), context()) ->
%% {[{Encoding::string(), Producer::function()}], reqdata(), context()}
%% @doc List the encodings available for representing this resource.
%% The encoding for a key-level request is the encoding that was
%% used in the PUT request that stored the document in Riak, or
%% "identity" and "gzip" if no encoding was specified at PUT-time.
encodings_provided(RD, Ctx0) ->
DocCtx = ensure_doc(Ctx0),
case DocCtx#ctx.doc of
{ok, _} ->
case select_doc(DocCtx) of
{MD, _} ->
case dict:find(?MD_ENCODING, MD) of
{ok, Enc} ->
{[{Enc, fun(X) -> X end}], RD, DocCtx};
error ->
{riak_kv_wm_utils:default_encodings(), RD, DocCtx}
end;
multiple_choices ->
{riak_kv_wm_utils:default_encodings(), RD, DocCtx}
end;
{error, _} ->
{riak_kv_wm_utils:default_encodings(), RD, DocCtx}
end.
%% @spec content_types_accepted(reqdata(), context()) ->
%% {[{ContentType::string(), Acceptor::atom()}],
%% reqdata(), context()}
%% @doc Get the list of content types this resource will accept.
%% Whatever content type is specified by the Content-Type header
%% of a key-level PUT request will be accepted by this resource.
%% (A key-level put *must* include a Content-Type header.)
content_types_accepted(RD, Ctx) ->
case wrq:get_req_header(?HEAD_CTYPE, RD) of
undefined ->
%% user must specify content type of the data
{[], RD, Ctx};
CType ->
Media = hd(string:tokens(CType, ";")),
case string:tokens(Media, "/") of
[_Type, _Subtype] ->
%% accept whatever the user says
{[{Media, accept_doc_body}], RD, Ctx};
_ ->
{[],
wrq:set_resp_header(
?HEAD_CTYPE,
"text/plain",
wrq:set_resp_body(
["\"", Media, "\""
" is not a valid media type"
" for the Content-type header.\n"],
RD)),
Ctx}
end
end.
%% @spec resource_exists(reqdata(), context()) -> {boolean(), reqdata(), context()}
%% @doc Determine whether or not the requested item exists.
%% Documents exists if a read request to Riak returns {ok, riak_object()},
%% and either no vtag query parameter was specified, or the value of the
%% vtag param matches the vtag of some value of the Riak object.
resource_exists(RD, Ctx0) ->
DocCtx = ensure_doc(Ctx0),
case DocCtx#ctx.doc of
{ok, Doc} ->
case DocCtx#ctx.vtag of
undefined ->
{true, RD, DocCtx};
Vtag ->
MDs = riak_object:get_metadatas(Doc),
{lists:any(fun(M) ->
dict:fetch(?MD_VTAG, M) =:= Vtag
end,
MDs),
RD, DocCtx#ctx{vtag=Vtag}}
end;
{error, _} ->
%% This should never actually be reached because all the error
%% conditions from ensure_doc are handled up in malformed_request.
{false, RD, DocCtx}
end.
%% @spec post_is_create(reqdata(), context()) -> {boolean(), reqdata(), context()}
%% @doc POST is considered a document-creation operation for bucket-level
%% requests (this makes webmachine call create_path/2, where the key
%% for the created document will be chosen).
post_is_create(RD, Ctx=#ctx{key=undefined}) ->
%% bucket-POST is create
{true, RD, Ctx};
post_is_create(RD, Ctx) ->
%% key-POST is not create
{false, RD, Ctx}.
%% @spec create_path(reqdata(), context()) -> {string(), reqdata(), context()}
%% @doc Choose the Key for the document created during a bucket-level POST.
%% This function also sets the Location header to generate a
%% 201 Created response.
create_path(RD, Ctx=#ctx{prefix=P, bucket=B, api_version=V}) ->
K = riak_core_util:unique_id_62(),
{K,
wrq:set_resp_header("Location",
riak_kv_wm_utils:format_uri(B, K, P, V),
RD),
Ctx#ctx{key=list_to_binary(K)}}.
%% @spec process_post(reqdata(), context()) -> {true, reqdata(), context()}
%% @doc Pass-through for key-level requests to allow POST to function
%% as PUT for clients that do not support PUT.
process_post(RD, Ctx) -> accept_doc_body(RD, Ctx).
%% @spec accept_doc_body(reqdata(), context()) -> {true, reqdat(), context()}
%% @doc Store the data the client is PUTing in the document.
%% This function translates the headers and body of the HTTP request
%% into their final riak_object() form, and executes the Riak put.
accept_doc_body(RD, Ctx=#ctx{bucket=B, key=K, client=C, links=L, index_fields=IF}) ->
Doc0 = case Ctx#ctx.doc of
{ok, D} -> D;
_ -> riak_object:new(B, K, <<>>)
end,
VclockDoc = riak_object:set_vclock(Doc0, decode_vclock_header(RD)),
{CType, Charset} = extract_content_type(RD),
UserMeta = extract_user_meta(RD),
CTypeMD = dict:store(?MD_CTYPE, CType, dict:new()),
CharsetMD = if Charset /= undefined ->
dict:store(?MD_CHARSET, Charset, CTypeMD);
true -> CTypeMD
end,
EncMD = case wrq:get_req_header(?HEAD_ENCODING, RD) of
undefined -> CharsetMD;
E -> dict:store(?MD_ENCODING, E, CharsetMD)
end,
LinkMD = dict:store(?MD_LINKS, L, EncMD),
UserMetaMD = dict:store(?MD_USERMETA, UserMeta, LinkMD),
IndexMD = dict:store(?MD_INDEX, IF, UserMetaMD),
MDDoc = riak_object:update_metadata(VclockDoc, IndexMD),
Doc = riak_object:update_value(MDDoc, riak_kv_wm_utils:accept_value(CType, wrq:req_body(RD))),
Options0 = case wrq:get_qs_value(?Q_RETURNBODY, RD) of ?Q_TRUE -> [returnbody]; _ -> [] end,
Options = make_options(Options0, Ctx),
case C:put(Doc, Options) of
{error, Reason} ->
handle_common_error(Reason, RD, Ctx);
ok ->
{true, RD, Ctx#ctx{doc={ok, Doc}}};
{ok, RObj} ->
DocCtx = Ctx#ctx{doc={ok, RObj}},
HasSiblings = (select_doc(DocCtx) == multiple_choices),
send_returnbody(RD, DocCtx, HasSiblings)
end.
%% Handle the no-sibling case. Just send the object.
send_returnbody(RD, DocCtx, _HasSiblings = false) ->
{Body, DocRD, DocCtx2} = produce_doc_body(RD, DocCtx),
{DocRD2, DocCtx3} = add_conditional_headers(DocRD, DocCtx2),
{true, wrq:append_to_response_body(Body, DocRD2), DocCtx3};
%% Handle the sibling case. Send either the sibling message body, or a
%% multipart body, depending on what the client accepts.
send_returnbody(RD, DocCtx, _HasSiblings = true) ->
AcceptHdr = wrq:get_req_header("Accept", RD),
case webmachine_util:choose_media_type(["multipart/mixed", "text/plain"], AcceptHdr) of
"multipart/mixed" ->
{Body, DocRD, DocCtx2} = produce_multipart_body(RD, DocCtx),
{DocRD2, DocCtx3} = add_conditional_headers(DocRD, DocCtx2),
{true, wrq:append_to_response_body(Body, DocRD2), DocCtx3};
_ ->
{Body, DocRD, DocCtx2} = produce_sibling_message_body(RD, DocCtx),
{DocRD2, DocCtx3} = add_conditional_headers(DocRD, DocCtx2),
{true, wrq:append_to_response_body(Body, DocRD2), DocCtx3}
end.
%% Add ETag and Last-Modified headers to responses that might not
%% necessarily include them, specifically when the client requests
%% returnbody on a PUT or POST.
add_conditional_headers(RD, Ctx) ->
{ETag, RD2, Ctx2} = generate_etag(RD, Ctx),
{LM, RD3, Ctx3} = last_modified(RD2, Ctx2),
RD4 = wrq:set_resp_header("ETag", webmachine_util:quoted_string(ETag), RD3),
RD5 = wrq:set_resp_header("Last-Modified",
httpd_util:rfc1123_date(calendar:universal_time_to_local_time(LM)), RD4),
{RD5,Ctx3}.
%% @spec extract_content_type(reqdata()) ->
%% {ContentType::string(), Charset::string()|undefined}
%% @doc Interpret the Content-Type header in the client's PUT request.
%% This function extracts the content type and charset for use
%% in subsequent GET requests.
extract_content_type(RD) ->
case wrq:get_req_header(?HEAD_CTYPE, RD) of
undefined ->
undefined;
RawCType ->
[CType|RawParams] = string:tokens(RawCType, "; "),
Params = [ list_to_tuple(string:tokens(P, "=")) || P <- RawParams],
{CType, proplists:get_value("charset", Params)}
end.
%% @spec extract_user_meta(reqdata()) -> proplist()
%% @doc Extract headers prefixed by X-Riak-Meta- in the client's PUT request
%% to be returned by subsequent GET requests.
extract_user_meta(RD) ->
lists:filter(fun({K,_V}) ->
lists:prefix(
?HEAD_USERMETA_PREFIX,
string:to_lower(riak_kv_wm_utils:any_to_list(K)))
end,
mochiweb_headers:to_list(wrq:req_headers(RD))).
%% @spec multiple_choices(reqdata(), context()) ->
%% {boolean(), reqdata(), context()}
%% @doc Determine whether a document has siblings. If the user has
%% specified a specific vtag, the document is considered not to
%% have sibling versions. This is a safe assumption, because
%% resource_exists will have filtered out requests earlier for
%% vtags that are invalid for this version of the document.
multiple_choices(RD, Ctx=#ctx{vtag=undefined, doc={ok, Doc}}) ->
%% user didn't specify a vtag, so there better not be siblings
case riak_object:get_update_value(Doc) of
undefined ->
case riak_object:value_count(Doc) of
1 -> {false, RD, Ctx};
_ -> {true, RD, Ctx}
end;
_ ->
%% just updated can't have multiple
{false, RD, Ctx}
end;
multiple_choices(RD, Ctx) ->
%% specific vtag was specified
%% if it's a tombstone add the X-Riak-Deleted header
case select_doc(Ctx) of
{M, _} ->
case dict:find(?MD_DELETED, M) of
{ok, "true"} ->
{false,
wrq:set_resp_header(?HEAD_DELETED, "true", RD),
Ctx};
error ->
{false, RD, Ctx}
end;
multiple_choices ->
throw({unexpected_code_path, ?MODULE, multiple_choices, multiple_choices})
end.
%% @spec produce_doc_body(reqdata(), context()) -> {binary(), reqdata(), context()}
%% @doc Extract the value of the document, and place it in the
%% response body of the request. This function also adds the
%% Link, X-Riak-Meta- headers, and X-Riak-Index- headers to the
%% response. One link will point to the bucket, with the
%% property "rel=container". The rest of the links will be
%% constructed from the links of the document.
produce_doc_body(RD, Ctx) ->
Prefix = Ctx#ctx.prefix,
Bucket = Ctx#ctx.bucket,
APIVersion = Ctx#ctx.api_version,
case select_doc(Ctx) of
{MD, Doc} ->
%% Add links to response...
Links1 = case dict:find(?MD_LINKS, MD) of
{ok, L} -> L;
error -> []
end,
Links2 = riak_kv_wm_utils:format_links([{Bucket, "up"}|Links1], Prefix, APIVersion),
LinkRD = wrq:merge_resp_headers(Links2, RD),
%% Add user metadata to response...
UserMetaRD = case dict:find(?MD_USERMETA, MD) of
{ok, UserMeta} ->
lists:foldl(fun({K,V},Acc) ->
wrq:merge_resp_headers([{K,V}],Acc)
end,
LinkRD, UserMeta);
error -> LinkRD
end,
%% Add index metadata to response...
IndexRD = case dict:find(?MD_INDEX, MD) of
{ok, IndexMeta} ->
lists:foldl(fun({K,V}, Acc) ->
K1 = riak_kv_wm_utils:any_to_list(K),
V1 = riak_kv_wm_utils:any_to_list(V),
wrq:merge_resp_headers([{?HEAD_INDEX_PREFIX ++ K1, V1}], Acc)
end,
UserMetaRD, IndexMeta);
error -> UserMetaRD
end,
{riak_kv_wm_utils:encode_value(Doc), encode_vclock_header(IndexRD, Ctx), Ctx};
multiple_choices ->
throw({unexpected_code_path, ?MODULE, produce_doc_body, multiple_choices})
end.
%% @spec produce_sibling_message_body(reqdata(), context()) ->
%% {iolist(), reqdata(), context()}
%% @doc Produce the text message informing the user that there are multiple
%% values for this document, and giving that user the vtags of those
%% values so they can get to them with the vtag query param.
produce_sibling_message_body(RD, Ctx=#ctx{doc={ok, Doc}}) ->
Vtags = [ dict:fetch(?MD_VTAG, M)
|| M <- riak_object:get_metadatas(Doc) ],
{[<<"Siblings:\n">>, [ [V,<<"\n">>] || V <- Vtags]],
wrq:set_resp_header(?HEAD_CTYPE, "text/plain",
encode_vclock_header(RD, Ctx)),
Ctx}.
%% @spec produce_multipart_body(reqdata(), context()) ->
%% {iolist(), reqdata(), context()}
%% @doc Produce a multipart body representation of an object with multiple
%% values (siblings), each sibling being one part of the larger
%% document.
produce_multipart_body(RD, Ctx=#ctx{doc={ok, Doc}, bucket=B, prefix=P}) ->
APIVersion = Ctx#ctx.api_version,
Boundary = riak_core_util:unique_id_62(),
{[[["\r\n--",Boundary,"\r\n",
riak_kv_wm_utils:multipart_encode_body(P, B, Content, APIVersion)]
|| Content <- riak_object:get_contents(Doc)],
"\r\n--",Boundary,"--\r\n"],
wrq:set_resp_header(?HEAD_CTYPE,
"multipart/mixed; boundary="++Boundary,
encode_vclock_header(RD, Ctx)),
Ctx}.
%% @spec select_doc(context()) -> {metadata(), value()}|multiple_choices
%% @doc Selects the "proper" document:
%% - chooses update-value/metadata if update-value is set
%% - chooses only val/md if only one exists
%% - chooses val/md matching given Vtag if multiple contents exist
%% (assumes a vtag has been specified)
select_doc(#ctx{doc={ok, Doc}, vtag=Vtag}) ->
case riak_object:get_update_value(Doc) of
undefined ->
case riak_object:get_contents(Doc) of
[Single] -> Single;
Mult ->
case lists:dropwhile(
fun({M,_}) ->
dict:fetch(?MD_VTAG, M) /= Vtag
end,
Mult) of
[Match|_] -> Match;
[] -> multiple_choices
end
end;
UpdateValue ->
{riak_object:get_update_metadata(Doc), UpdateValue}
end.
%% @spec encode_vclock_header(reqdata(), context()) -> reqdata()
%% @doc Add the X-Riak-Vclock header to the response.
encode_vclock_header(RD, #ctx{doc={ok, Doc}}) ->
{Head, Val} = riak_object:vclock_header(Doc),
wrq:set_resp_header(Head, Val, RD);
encode_vclock_header(RD, #ctx{doc={error, {deleted, VClock}}}) ->
BinVClock = riak_object:encode_vclock(VClock),
wrq:set_resp_header(?HEAD_VCLOCK, binary_to_list(base64:encode(BinVClock)), RD).
%% @spec decode_vclock_header(reqdata()) -> vclock()
%% @doc Translate the X-Riak-Vclock header value from the request into
%% its Erlang representation. If no vclock header exists, a fresh
%% vclock is returned.
decode_vclock_header(RD) ->
case wrq:get_req_header(?HEAD_VCLOCK, RD) of
undefined -> vclock:fresh();
Head -> riak_object:decode_vclock(base64:decode(Head))
end.
%% @spec ensure_doc(context()) -> context()
%% @doc Ensure that the 'doc' field of the context() has been filled
%% with the result of a riak_client:get request. This is a
%% convenience for memoizing the result of a get so it can be
%% used in multiple places in this resource, without having to
%% worry about the order of executing of those places.
ensure_doc(Ctx=#ctx{doc=undefined, key=undefined}) ->
Ctx#ctx{doc={error, notfound}};
ensure_doc(Ctx=#ctx{doc=undefined, bucket=B, key=K, client=C,
basic_quorum=Quorum, notfound_ok=NotFoundOK}) ->
Options0 = [deletedvclock, {basic_quorum, Quorum},
{notfound_ok, NotFoundOK}],
Options = make_options(Options0, Ctx),
Ctx#ctx{doc=C:get(B, K, Options)};
ensure_doc(Ctx) -> Ctx.
%% @spec delete_resource(reqdata(), context()) -> {true, reqdata(), context()}
%% @doc Delete the document specified.
delete_resource(RD, Ctx=#ctx{bucket=B, key=K, client=C}) ->
Options = make_options([], Ctx),
Result = case wrq:get_req_header(?HEAD_VCLOCK, RD) of
undefined ->
C:delete(B,K,Options);
_ ->
C:delete_vclock(B,K,decode_vclock_header(RD),Options)
end,
case Result of
{error, Reason} ->
handle_common_error(Reason, RD, Ctx);
ok ->
{true, RD, Ctx}
end.
%% @spec generate_etag(reqdata(), context()) ->
%% {undefined|string(), reqdata(), context()}
%% @doc Get the etag for this resource.
%% Documents will have an etag equal to their vtag. For documents with
%% siblings when no vtag is specified, this will be an etag derived from
%% the vector clock.
generate_etag(RD, Ctx) ->
case select_doc(Ctx) of
{MD, _} ->
{dict:fetch(?MD_VTAG, MD), RD, Ctx};
multiple_choices ->
{ok, Doc} = Ctx#ctx.doc,
<<ETag:128/integer>> = crypto:md5(term_to_binary(riak_object:vclock(Doc))),
{riak_core_util:integer_to_list(ETag, 62), RD, Ctx}
end.
%% @spec last_modified(reqdata(), context()) ->
%% {undefined|datetime(), reqdata(), context()}
%% @doc Get the last-modified time for this resource.
%% Documents will have the last-modified time specified by the riak_object.
%% For documents with siblings, this is the last-modified time of the latest
%% sibling.
last_modified(RD, Ctx) ->
case select_doc(Ctx) of
{MD, _} ->
{normalize_last_modified(MD),RD, Ctx};
multiple_choices ->
{ok, Doc} = Ctx#ctx.doc,
LMDates = [ normalize_last_modified(MD) ||
MD <- riak_object:get_metadatas(Doc) ],
{lists:max(LMDates), RD, Ctx}
end.
%% @spec normalize_last_modified(dict()) -> calendar:datetime()
%% @doc Extract and convert the Last-Modified metadata into a normalized form
%% for use in the last_modified/2 callback.
normalize_last_modified(MD) ->
case dict:fetch(?MD_LASTMOD, MD) of
Now={_,_,_} ->
calendar:now_to_universal_time(Now);
Rfc1123 when is_list(Rfc1123) ->
httpd_util:convert_request_date(Rfc1123)
end.
%% @spec get_link_heads(reqdata(), context()) -> [link()]
%% @doc Extract the list of links from the Link request header.
%% This function will die if an invalid link header format
%% is found.
get_link_heads(RD, Ctx) ->
APIVersion = Ctx#ctx.api_version,
Prefix = Ctx#ctx.prefix,
Bucket = Ctx#ctx.bucket,
%% Get a list of link headers...
LinkHeaders1 =
case wrq:get_req_header(?HEAD_LINK, RD) of
undefined -> [];
Heads -> string:tokens(Heads, ",")
end,
%% Decode the link headers. Throw an exception if we can't
%% properly parse any of the headers...
{BucketLinks, KeyLinks} =
case APIVersion of
1 ->
{ok, BucketRegex} = re:compile("</" ++ Prefix ++ "/([^/]+)>; ?rel=\"([^\"]+)\""),
{ok, KeyRegex} = re:compile("</" ++ Prefix ++ "/([^/]+)/([^/]+)>; ?riaktag=\"([^\"]+)\""),
extract_links(LinkHeaders1, BucketRegex, KeyRegex);
2 ->
{ok, BucketRegex} = re:compile("</buckets/([^/]+)>; ?rel=\"([^\"]+)\""),
{ok, KeyRegex} = re:compile("</buckets/([^/]+)/keys/([^/]+)>; ?riaktag=\"([^\"]+)\""),
extract_links(LinkHeaders1, BucketRegex, KeyRegex)
end,
%% Validate that the only bucket header is pointing to the parent
%% bucket...
IsValid = (BucketLinks == []) orelse (BucketLinks == [{Bucket, <<"up">>}]),
case IsValid of
true ->
KeyLinks;
false ->
throw({invalid_link_headers, LinkHeaders1})
end.
%% Run each LinkHeader string() through the BucketRegex and
%% KeyRegex. Return {BucketLinks, KeyLinks}.
extract_links(LinkHeaders, BucketRegex, KeyRegex) ->
%% Run each regex against each string...
extract_links_1(LinkHeaders, BucketRegex, KeyRegex, [], []).
extract_links_1([LinkHeader|Rest], BucketRegex, KeyRegex, BucketAcc, KeyAcc) ->
case re:run(LinkHeader, BucketRegex, [{capture, all_but_first, list}]) of
{match, [Bucket, Tag]} ->
Bucket1 = list_to_binary(mochiweb_util:unquote(Bucket)),
Tag1 = list_to_binary(mochiweb_util:unquote(Tag)),
NewBucketAcc = [{Bucket1, Tag1}|BucketAcc],
extract_links_1(Rest, BucketRegex, KeyRegex, NewBucketAcc, KeyAcc);
nomatch ->
case re:run(LinkHeader, KeyRegex, [{capture, all_but_first, list}]) of