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if not modules then modules = { } end modules ['util-sql-imp-library'] = {
version = 1.001,
comment = "companion to util-sql.lua",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
-- local function pcall(f,...) return true, f(...) end
-- For some reason the sql lib partially fails in luatex when creating hashed row. So far
-- we couldn't figure it out (some issue with adapting the table that is passes as first
-- argument in the fetch routine. Apart from this it looks like the mysql binding has some
-- efficiency issues (like creating a keys and types table for each row) but that could be
-- optimized. Anyhow, fecthing results can be done as follows:
-- local function collect_1(r)
-- local t = { }
-- for i=1,r:numrows() do
-- t[#t+1] = r:fetch({},"a")
-- end
-- return t
-- end
--
-- local function collect_2(r)
-- local keys = r:getcolnames()
-- local n = #keys
-- local t = { }
-- for i=1,r:numrows() do
-- local v = { r:fetch() }
-- local r = { }
-- for i=1,n do
-- r[keys[i]] = v[i]
-- end
-- t[#t+1] = r
-- end
-- return t
-- end
--
-- local function collect_3(r)
-- local keys = r:getcolnames()
-- local n = #keys
-- local t = { }
-- for i=1,r:numrows() do
-- local v = r:fetch({},"n")
-- local r = { }
-- for i=1,n do
-- r[keys[i]] = v[i]
-- end
-- t[#t+1] = r
-- end
-- return t
-- end
--
-- On a large table with some 8 columns (mixed text and numbers) we get the following
-- timings (the 'a' alternative is already using the more efficient variant in the
-- binding).
--
-- collect_1 : 1.31
-- collect_2 : 1.39
-- collect_3 : 1.75
--
-- Some, as a workaround for this 'bug' the second alternative can be used.
local format = string.format
local lpegmatch = lpeg.match
local setmetatable, type = setmetatable, type
local trace_sql = false trackers.register("sql.trace", function(v) trace_sql = v end)
local trace_queries = false trackers.register("sql.queries",function(v) trace_queries = v end)
local report_state = logs.reporter("sql","library")
local sql = utilities.sql
local mysql = require("luasql.mysql")
local cache = { }
local helpers = sql.helpers
local methods = sql.methods
local validspecification = helpers.validspecification
local querysplitter = helpers.querysplitter
local dataprepared = helpers.preparetemplate
local serialize = sql.serialize
local deserialize = sql.deserialize
local formatters = string.formatters
local initialize = mysql.mysql
local function connect(session,specification)
return session:connect(
specification.database or "",
specification.username or "",
specification.password or "",
specification.host or "",
specification.port
)
end
local function fetched(specification,query,converter)
if not query or query == "" then
report_state("no valid query")
return false
end
local id = specification.id
local session, connection
if id then
local c = cache[id]
if c then
session = c.session
connection = c.connection
end
if not connection then
session = initialize()
if not session then
return formatters["no session for %a"](id)
end
connection = connect(session,specification)
if not connection then
return formatters["no connection for %a"](id)
end
cache[id] = { session = session, connection = connection }
end
else
session = initialize()
if not session then
return "no session"
end
connection = connect(session,specification)
if not connection then
return "no connection"
end
end
if not connection then
report_state("error in connection: %s@%s to %s:%s",
specification.database or "no database",
specification.username or "no username",
specification.host or "no host",
specification.port or "no port"
)
return "no connection"
end
query = lpegmatch(querysplitter,query)
local result, okay
for i=1,#query do
local q = query[i]
local r, m = connection:execute(q)
if m then
report_state("error in query to host %a: %s",specification.host,string.collapsespaces(q or "?"))
if m then
report_state("message: %s",m)
end
end
local t = type(r)
if t == "userdata" then
result = r
okay = true
elseif t == "number" then
okay = true
end
end
if not okay then -- can go
if session then
session:close()
end
if connection then
connection:close()
end
if id then
cache[id] = nil
end
return "execution error"
end
local data, keys
if result then
if converter then
data = converter.library(result)
else
keys = result:getcolnames()
if keys then
data = { }
local n = result:numrows() or 0
if n > 0 then
local k = #keys
for i=1,n do
local v = { result:fetch() }
local d = { }
for i=1,k do
d[keys[i]] = v[i]
end
data[#data+1] = d
end
end
end
end
result:close()
end
if not id then
if connection then
connection:close()
end
if session then
session:close()
end
end
return false, data, keys
end
local function datafetched(specification,query,converter)
local callokay, connectionerror, data, keys = pcall(fetched,specification,query,converter)
if not callokay then
report_state("call error, retrying")
callokay, connectionerror, data, keys = pcall(fetched,specification,query,converter)
elseif connectionerror then
report_state("error: %s, retrying",connectionerror)
callokay, connectionerror, data, keys = pcall(fetched,specification,query,converter)
end
if not callokay then
report_state("persistent call error")
elseif connectionerror then
report_state("persistent error: %s",connectionerror)
end
return data or { }, keys or { }
end
local function execute(specification)
if trace_sql then
report_state("executing library")
end
if not validspecification(specification) then
report_state("error in specification")
return
end
local query = dataprepared(specification)
if not query then
report_state("error in preparation")
return
end
local data, keys = datafetched(specification,query,specification.converter)
if not data then
report_state("error in fetching")
return
end
local one = data[1]
if one then
setmetatable(data,{ __index = one } )
end
return data, keys
end
-- Here we build the dataset stepwise so we don't use the data hack that
-- is used in the client variant.
local wraptemplate = [[
local converters = utilities.sql.converters
local deserialize = utilities.sql.deserialize
local tostring = tostring
local tonumber = tonumber
local booleanstring = string.booleanstring
%s
return function(result)
if not result then
return { }
end
local nofrows = result:numrows() or 0
if nofrows == 0 then
return { }
end
local target = { } -- no %s needed here
for i=1,nofrows do
local cells = { result:fetch() }
target[%s] = {
%s
}
end
return target
end
]]
local celltemplate = "cells[%s]"
methods.library = {
runner = function() end, -- never called
execute = execute,
initialize = initialize, -- returns session
usesfiles = false,
wraptemplate = wraptemplate,
celltemplate = celltemplate,
}
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