1. A computer-implemented method for improving efficiency in a delta compression process in a data storage system, the method comprising:
selecting a data chunk to delta compress;
generating a sketch for the selected data chunk;
searching for a set of candidate data chunks using the sketch;
ranking the set of candidate data chunks by degree of sketch matching;
tie-breaking the set of candidate data chunks, where the set of candidate data chunks has an equal degree of sketch matching, using location status data for each candidate data chunk, wherein the location status data indicates the location and status of the candidate data chunk and the location status data is at least one of a compressed in a cache status, a decompressed in a cache status, or a compressed in a data storage status, wherein tie-breaking the set of candidate data chunks prefers a decompressed in a cache status over a compressed in a cache status;
delta compressing the selected data chunk with a selected candidate data chunk; and
storing the delta compressed selected data chunk in the data storage system.
2. The method of claim 1, wherein generating the sketch further comprises: generating a set of features for the selected data chunk.
3. The method of claim 2, wherein searching for the set of candidate data chunks further comprises:
searching an index of data chunks to identify the set of candidate data chunks by comparing features in the index with the set of features of the selected data chunk.
4. The method of claim 1, wherein ranking the set of candidates data chunks by degree of sketch matching further comprises:
ranking the set of candidates by a number of matching features between a candidate and the selected data chunk.
5. The method of claim 1, wherein tie-breaking the set of candidate data chunks using location status data for each candidate prefers a compressed in a cache status over a compressed in a data storage status.
6. The method of claim 1, wherein tie-breaking the set of candidate data chunks using location status data for each candidate orders the set of candidate data chunks based on access times to retrieve each candidate data chunk.
7. A non-transitory computer-readable storage medium having instructions stored therein, which when executed by a computer, cause the computer to perform a method, the method for improving efficiency in a delta compression process, the method comprising:
selecting a data chunk to delta compress;
generating a sketch for the selected data chunk;
searching for a set of candidate data chunks using the sketch;
ranking the set of candidate data chunks by degree of sketch matching;
tie-breaking the set of candidate data chunks, where the set of candidate data chunks has an equal degree of sketch matching, using location status data for each candidate data chunk, wherein the location status data indicates the location and status of the candidate data chunk and the location status data is at least one of a compressed in a cache status, a decompressed in a cache status, or a compressed in a data storage status, wherein tiebreaking the set of candidates data chunks prefers a compressed in a cache status over a compressed in a data storage status;
delta compressing the selected data chunk with a selected candidate data chunk; and
storing the delta compressed selected data chunk in a data storage system.
8. The non-transitory computer-readable storage medium of claim 7, wherein generating the sketch further comprises:
generating a set of features for the selected data chunk.
9. The non-transitory computer-readable storage medium of claim 8, wherein searching for the set of candidate data chunks further comprises:
searching an index of data chunks to identify the set of candidate data chunks by comparing features in the index with the set of features of the selected data chunk.
10. The non-transitory computer-readable storage medium of claim 7, wherein ranking the set of candidates data chunks by degree of sketch matching further comprises: ranking the set of candidates by a number of matching features between a candidate and the selected data chunk.
11. The non-transitory computer-readable storage medium of claim 7, wherein tiebreaking the set of candidate data chunks using location status data for each candidate prefers a decompressed in a cache status over a compressed in a cache status.
12. The non-transitory computer-readable storage medium of claim 7, wherein tiebreaking the set of candidate data chunks using location status data for each candidate orders the set of candidate data chunks based on access times to retrieve each candidate data chunk.
13. A delta compression system, comprising:
a delta processing module to delta compress a first set of data chunks; and
a cache to store a second set of data chunks;
a data storage system to store a third set of data chunks;
a preferential selection module coupled to the cache, data storage system and delta processing module, the preferential selection module to identify a candidate to serve as a base chunk for delta compression by ranking a set of candidate base chunks from the second set of data chunks and third set of data chunks by similarity to a data chunk from the first set of data chunks then tie-breaking a ranked set of candidate data chunks, where the set of candidate data chunks has an equal degree of sketch matching, using location status information, wherein the location status data indicates the location and status of the candidate data chunk and the location status data is at least one of a compressed in a cache status, a decompressed in a cache status, or a compressed in a data storage status, wherein tie-breaking the set of candidate data chunks prefers a decompressed in a cache status over a compressed in a cache status.
14. The delta compression system of claim 13, wherein tie-breaking the set of candidate data chunks using location status data for each candidate prefers a compressed in a cache status over a compressed in a data storage status.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of manufacturing a plastic lens, the plastic lens comprising a lens part and a flange part on a periphery of the lens part, the flange part having a flange surface on at least one side of the flange part, a depressed part formed on at least a part of the flange surface, an outer portion formed on an outer side of the depressed part, and a marking on the depressed part, the method comprising the steps of:
preparing first and second molding dies, the first molding die comprising a first nested portion for forming the lens part and a second portion for forming the flange part, the first nested portion being separable against the second portion;
positioning the first and second molding dies to form a mold cavity; and
injecting a resin material to the mold cavity, the marking being formed by the second portion of the first molding die,
wherein the second portion has a concave portion for forming the marking on a surface thereof that corresponds to the depressed part, and a position of a deepest point of the concave portion is shallower than a point of the second portion which corresponds to a highest point of the outer part.
2. The method of manufacturing a plastic lens according to claim 1, wherein a boundary between the first portion and the second portion is positioned around an inner periphery of the flange surface.
3. The method of manufacturing a plastic lens according to claim 1, wherein a surface of the second portion around the concave portion is mirror-finished.
4. The method of manufacturing a plastic lens according to claim 1, wherein the first nested portion rotates without changing its placed position.
5. A method of manufacturing a plastic lens, the plastic lens comprising a lens part having an optical function portion and a flange part on a periphery of the lens part, the flange part having a flange surface on at least one side of the flange part, a depressed part formed on at least a part of the flange surface, an outer portion formed on an outer side of the depressed part, and a plurality of markings on the depressed part, the method comprising the steps of:
preparing first and second molding dies, the first molding die comprising a first nested portion for forming at least the optical function portion and a second portion for forming the flange part, the first nested portion being separable against the second portion;
positioning the first and second molding dies to form a mold cavity; and
injecting a resin material to the mold cavity, the plurality of markings being formed by the second portion of the first molding die,
wherein the second portion has a plurality of concave portions for forming the plurality of markings on a surface thereof that corresponds to the depressed part, and a position of a deepest point of the concave portions is shallower than a point of the second portion which corresponds to a highest point of the outer part.
6. The method of manufacturing a plastic lens according to claim 5, wherein the plurality of concave portions have two or more different shapes.
7. The method of manufacturing a plastic lens according to claim 5, wherein the plurality of concave portions have substantially a same shape, a first marking is formed by a single concave portion, and a second marking is formed by parallel concave portions.
8. The method of manufacturing a plastic lens according to claim 5, wherein a relative position of the plurality of concave portions is set so as to show a predetermined information of the mold cavity or the first molding die.
9. The method of manufacturing a plastic lens according to claim 5, wherein surfaces of the second portion around each of the plurality of concave portions are mirror-finished.
10. The method of manufacturing a plastic lens according to claim 5, wherein the first nested portion rotates without changing its placed position.
11. The method of manufacturing a plastic lens according to claim 7, wherein a relative position of the first and second markings is determined according to a type of production jig used to produce the plastic lens.
12. The method of manufacturing a plastic lens according to claim 7, wherein a surface of the depressed part is mirror-finished at least in a vicinity of a portion to form the first marking.
13. The method of manufacturing a plastic lens according to claim 5, wherein the boundary between the first nested portion and the second portion is positioned around an inner periphery of the flange surface.
14. The method of manufacturing a plastic lens according to claim 5, wherein the second molding die comprises a third nested portion for forming the lens part and a fourth portion for forming the flange part, the third nested portion being separable against the fourth portion, and wherein a width of the third nested portion is larger than a width of the first nested portion.
15. A method of manufacturing a plastic lens, the plastic lens comprising a lens part having an optical function portion and a flange part on a periphery of the lenst part, the flange part having a flange surface on at least one side of the flange part, and a plurality of markings, the method comprising the steps of:
preparing first and second molding dies, the first molding die having a separable nested portion for forming at least the optical function portion;
positioning the first and second molding dies to form a mold cavity; and
injecting a resin material to the mold cavity, the plurality of markings being formed by a plurality of concave portions formed on a surface of the first molding die except the nested portion,
wherein the plastic lens is used as a pick-up plastic lens, the lens part has a convex lens surface, and the flange surface comprises a first surface higher than the convex lens surface, and a second surface lower than the first surface and positioned inner than the first surface, and
the first molding die comprises a first nested portion, which is equal to the separable nested portion, and a second portion for forming the flange part, the second portion having a first concave portion for forming the marking on a surface thereof that corresponds to the second surface, a position of a deepest point of the first concave portion being shallower than a point of the second portion which corresponds to a highest point of the flange surface.
16. The method of manufacturing a plastic lens according to claim 15, wherein the first nested portion rotates without changing its placed position.
17. The method of manufacturing a plastic lens according to claim 15, wherein the second molding die comprises a third nested portion for forming the lens part and a fourth portion for forming the flange part, the third nested portion being separable against the fourth portion, and wherein a width of the third nested portion is larger than a width of the first nested portion.
18. A method of manufacturing a plastic lens, the plastic lens comprising a lens part having an optical function portion and a flange part on a periphery of the lens part, the flange part having a flange surface on at least one side of the flange part, a depressed part formed on at least a part of the flange surface, an outer portion formed on an outer side of the depressed part, and first and second markings on the depressed part, the method comprising the steps of:
preparing first and second molding dies, the first molding die having first and second concave portions for forming the first and second markings on a surface of the depressed part;
positioning the first and second molding dies to form a mold cavity; and
injecting a resin material to the mold cavity through a gate, the first and second markings being formed by the first and second concave portions of the first molding die;
wherein a position of a deepest point of the first and second concave portions is shallower than a point of the first molding die which corresponds to a highest point of the outer part, and a position of the first molding die which corresponds to the lens part is shallower than a point of the first molding die which corresponds to a highest point of the outer part.
19. The method of manufacturing a plastic lens according to claim 18, wherein the first marking indicates the position of the gate, and a relative position of the first and second markings is determined according to a type of production jig used to produce the plastic lens.
20. The method of manufacturing a plastic lens according to claim 18, wherein a surface of the depressed part is mirror-finished at least in a vicinity of a portion to form the first marking.
21. The method of manufacturing a plastic lens according to claim 19, wherein a surface of the depressed part is mirror-finished at least in a vicinity of a portion to form the first marking.