摘要:
Techniques are provided for performing transaction-aware caching of metadata in an electronic file system. A mechanism is described for providing transaction-aware caching that uses a cache hierarchy, where the cache hierarchy includes uncommitted caches associated with sessions in an application and a committed cache that is shared among the sessions in that application. Techniques are described for caching document metadata, access control metadata and folder path metadata. Also described is a technique for using negative cache entries to avoid unnecessary communications with a server when applications repeatedly request non-existent data.
摘要:
A method and apparatus for associating methods or attributes on a per-instance basis is provided. One technique for providing “per-instance attributes” involves properties and property bundles. A second technique for providing “per-instance attributes” involves categories wherein the instance can be thought of as being “placed” into one or more categories. A technique for providing “per-instance methods” involves policies. In any of these techniques, providing per-instance properties may be used in any of the following ways: (1) different instances of the same class are associated with different properties where the properties are not in the class; and (2) two instances of two different classes are associated with the same property where the property is not in either of the two classes.
摘要:
Techniques are provided for performing transaction-aware caching of metadata in an electronic file system. A mechanism is described for providing transaction-aware caching that uses a cache hierarchy, where the cache hierarchy includes uncommitted caches associated with sessions in an application and a committed cache that is shared among the sessions in that application. Techniques are described for caching document metadata, access control metadata and folder path metadata. Also described is a technique for using negative cache entries to avoid unnecessary communications with a server when applications repeatedly request non-existent data.
摘要:
A method and apparatus for associating methods or attributes on a per-instance basis is provided. One technique for providing “per-instance attributes” involves properties and property bundles. A second technique for providing “per-instance attributes” involves categories wherein the instance can be thought of as being “placed” into one or more categories. A technique for providing “per-instance methods” involves policies. In any of these techniques, providing per-instance properties may be used in any of the following ways: (1) different instances of the same class are associated with different properties where the properties are not in the class; and (2) two instances of two different classes are associated with the same property where the property is not in either of the two classes.
摘要:
A method and apparatus for associating methods or attributes on a per-instance basis is provided. One technique for providing “per-instance attributes” involves properties and property bundles. A second technique for providing “per-instance attributes” involves categories wherein the instance can be thought of as being “placed” into one or more categories. A technique for providing “per-instance methods” involves policies. In any of these techniques, providing per-instance properties may be used in any of the following ways: (1) different instances of the same class are associated with different properties where the properties are not in the class; and (2) two instances of two different classes are associated with the same property where the property is not in either of the two classes.
摘要:
A process of preparing a copolymer of a vinyl monomer such as vinyl acetate, vinyl propionate and vinyl trifluoroacetate, and of fluorinated monomer such as tetrafluoroethylene and trifluoroethylene, said copolymer having an alternating or substantially alternating distributing of vinyl recurring monomeric units and fluorinated recurring monomeric units in the copolymers backbone which comprises copolymerizing said monomers in a reaction medium of a chlorocarbon, a fluorocarbon a chlorofluorocarbon or a mixture thereof.
摘要:
A process of preparing a copolymer of vinyl monomer selected from the group consisting of vinyl acetate, vinyl propionate and vinyl trifluoroacetate, and of fluorinated monomer selected from the group consisting of tetrafluoroethylene and trifluoroethylene, said copolymer having an alternating or substantially alternating distribution of vinyl recurring monomeric units and fluorinated recurring monomeric units in the copolymer backbone which comprises copolymerizing said monomers in an aqueous reaction medium comprising water and a water miscible organic co-solvent in an amount less than the amount sufficient to form a distinct organic co-solvent phase.
摘要:
The present invention is directed to a copolymer of a fluoromonomer having the formula R.sub.1 R.sub.2 C=CR.sub.3 F wherein R.sub.1, R.sub.2 and R.sub.3 are selected from H and F, and R.sub.3 may be Cl when R.sub.1 and R.sub.2 are F; and a vinyl monomer having the formula H.sub.2 C=CHR.sub.x, wherein R.sub.x is a radical having the formula --O.sub.2 CR.sub.y, wherein R.sub.y is a radical selected from CH.sub.3 and C.sub.2 H.sub.5.The resulting copolymer comprises fluorinated units having the formula (R.sub.1 R.sub.2 C-CR.sub.3 F) wherein R.sub.1, R.sub.2 and R.sub.3 are selected from H and F, and R.sub.3 may be Cl when R.sub.1 and R.sub.2 are F, and corresponding amounts of vinyl units having the formula (H.sub.2 C-CHR.sub.x), wherein R.sub.x is selected from --CH.sub.3 and C.sub.2 H.sub.5. In an alternate and preferred embodiment the copolymer is hydrolyzed so that R.sub.x becomes --OH.
摘要:
This invention relates to novel fluorinated compounds derived from 3,3',4,4'-benzophenone tetracarboxylic dianhydride that are useful as surface modifiers for various fibers. The novel compounds contain two fluorinated ester derived from fluorinated alcohols and two esters derived from oxirane compounds.