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#########################################################################
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# This file is part of CoCalc: Copyright © 2020 Sagemath, Inc.
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# License: MS-RSL – see LICENSE.md for details
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#########################################################################
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# Blobs
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winston = require('./logger').getLogger('blobs')
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misc_node = require('@cocalc/backend/misc_node')
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misc    = require('@cocalc/util/misc')
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{defaults, required} = misc
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{MAX_BLOB_SIZE} = require('@cocalc/util/db-schema/blobs')
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# save a blob in the blobstore database with given misc_node.uuidsha1 hash.
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exports.save_blob = (opts) ->
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    opts = defaults opts,
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        uuid       : undefined  # uuid=sha1-based from blob; actually *required*, but instead of a traceback, get opts.cb(err)
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        blob       : undefined  # actually *required*, but instead of a traceback, get opts.cb(err)
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        ttl        : undefined  # object in blobstore will have *at least* this ttl in seconds;
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                           # if there is already something, in blobstore with longer ttl, we leave it; undefined = infinite ttl
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        check      : true       # if true, return an error (via cb) if misc_node.uuidsha1(opts.blob) != opts.uuid.
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                           # This is a check against bad user-supplied data.
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        project_id : undefined
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        account_id : undefined
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        database   : required
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        cb         : required   # cb(err, ttl actually used in seconds); ttl=0 for infinite ttl
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    dbg = (m) -> winston.debug("save_blob(uuid=#{opts.uuid}): #{m}")
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    dbg()
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    err = undefined
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    if not opts.blob?
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        err = "save_blob: UG -- error in call to save_blob (uuid=#{opts.uuid}); received a save_blob request with undefined blob"
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    else if not opts.uuid?
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        err = "save_blob: BUG -- error in call to save_blob; received a save_blob request without corresponding uuid"
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    else if not opts.project_id?
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        err = "save_blob: BUG -- error in call to save_blob; received a save_blob request without corresponding project_id"
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    else if opts.blob.length > MAX_BLOB_SIZE
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        err = "save_blob: blobs are limited to #{misc.human_readable_size(MAX_BLOB_SIZE)} and you just tried to save one of size #{opts.blob.length/1000000}MB"
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    else if opts.check and opts.uuid != misc_node.uuidsha1(opts.blob)
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        err = "save_blob: uuid=#{opts.uuid} must be derived from the Sha1 hash of blob, but it is not (possible malicious attack)"
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    if err
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        dbg(err)
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        opts.cb(err)
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        return
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    # Store the blob in the database, if it isn't there already.
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    opts.database.save_blob
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        uuid       : opts.uuid
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        blob       : opts.blob
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        ttl        : opts.ttl
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        project_id : opts.project_id
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        account_id : opts.account_id
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        cb         : (err, ttl) =>
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            if err
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                dbg("failed to store blob -- #{err}")
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            else
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                dbg("successfully stored blob")
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            opts.cb(err, ttl)
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