Efficient index processing
First Claim
1. A method of tracking a plurality of file system objects being stored, wherein the plurality of objects is associated with a saveset, comprising:
- providing a bitmap;
applying a hash function to a name of each file system object to generate a hash value k;
setting the kth bit in the bitmap to ON;
storing the bitmap as a hint in an index, wherein the hint is associated with the saveset; and
wherein applying the hash function includes applying an equation
s[0]*xk+s[1]*xk−
1+s[2]*xk−
2+ . . . +s[k−
1]*x1+s[k]*x0 wherein x equals 231.
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Accused Products
Abstract
A method, article of manufacture, and apparatus for tracking a plurality of objects being stored are disclosed. In an embodiment, this comprises computing the hash value of the name of each object being stored, setting the corresponding bits in a bitmap, and storing the bitmap as a hint in an index. The size of the bitmap is determined by the space available for storing the hint, and the range of hash values is determined by the size of the bitmap. The range may be determined by choosing a prime number smaller than the space available for storing the bitmap. Either the hint or the longest pathname containing the objects can be stored, and this may be selected based on the application.
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Citations
17 Claims
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1. A method of tracking a plurality of file system objects being stored, wherein the plurality of objects is associated with a saveset, comprising:
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providing a bitmap; applying a hash function to a name of each file system object to generate a hash value k; setting the kth bit in the bitmap to ON; storing the bitmap as a hint in an index, wherein the hint is associated with the saveset; and wherein applying the hash function includes applying an equation
s[0]*xk+s[1]*xk−
1+s[2]*xk−
2+ . . . +s[k−
1]*x1+s[k]*x0wherein x equals 231. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of tracking a plurality of file system objects being stored, wherein the plurality of objects is associated with a saveset, comprising:
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providing a bitmap; applying a hash function to a name of each file system object to generate a hash value k; setting the kth bit in the bitmap to ON; storing in an index, the bitmap as a hint or a longest pathname containing the plurality of objects, wherein the hint is associated with the saveset; and wherein applying the hash function further includes applying an equation
h(k)=k mod m.- View Dependent Claims (14, 15, 16)
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17. A computer program product for tracking a plurality of file system objects being stored, wherein the plurality of objects is associated with a saveset, comprising a computer usable medium having machine readable code embodied therein for:
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providing a bitmap; applying a hash function to a name of each file system object to generate a hash value k; setting the kth bit in the bitmap to ON; storing the bitmap as a hint in an index, wherein the hint is associated with the saveset; and wherein applying the hash function further includes applying an equation
h(k)=k mod m.
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Specification