Abstract: An extracting method that is executed by a computer. The extracting method includes storing first information into a storage device, wherein the first information indicates for each of a plurality of files and for each of a plurality of character data, whether the file includes the character data; storing second information into the storage device when a given file included in the files is updated, wherein the second information indicates for each of the character data, whether the given file includes the character data; and extracting a file group from the files when a search request is received, wherein from the file group, a file is excluded that is indicated by the first information and the second information not to include a character data to be searched for included in the search request.

Abstract: An encrypting method including encrypting a first data segment of encryption target data on the basis of first key information, generating second key information on the basis of the first data segment by using a predetermined algorithm, and encrypting a second data segment of the encryption target data, which is different from the first data segment, on the basis of the second key information.

Abstract: A compression file formed by compressing an object file is compared in a compressed state with a compression code string that matches with a compression character string of a character string to be searched for. The compression code string acquiring no match as the result of the comparison is decompressed as it is. On the other hand, the compression code string acquiring match is substituted with a substituted character string in a comparison and substitution table generated in advance.

Abstract: A computer-readable recording medium stores a program causing a computer to execute tabulating a number of character data types for each compression code length specified by an occurrence probability corresponding to an appearance rate of each character data in a file; determining an upper limit_N of compression code length assigned to the character data, among lengths from a minimum to a maximum compression code length and based on the total number of character data types; correcting the number of character data types for the upper limit_N, to the sum of the numbers of character data types for the compression code lengths at least equal to the upper limit_N; and constructing a 2N-branch nodeless Huffman tree with the maximum branch number defined as the upper limit_N and leaves that are compression codes of lengths corresponding to occurrence probabilities of the character data, based on the numbers of character data types post-correction.

Abstract: A retrieving apparatus includes a processor that specifies in each tier of synonym dictionary data, classification codes of a search word in a search character string and those of a comparison word in character strings for comparison; extracts from among the specified classification codes, classification codes in a specific tier; judges for each character string for comparison, whether the extracted classification code of the search word and that of the comparison word match; counts for the specific tier, matching classification codes; determines based on the count, whether a character string is to be excluded whose classification code of the comparison word for the specific tier does not match that of the search word; calculates based on the specified classification code of the search word and that of the comparison word in the character string not to be excluded, similarity between the two character strings; and outputs a calculation result.

Abstract: A searching apparatus includes a processor configured to receive searching character information, in a case that document data includes a designation that first character information and second character information are provided in adscript description, to copy state information indicating a state of a collating process of the searching character information on third character information in front of the designation in the document data, to update the state information based on a result of collating the first character information with the searching character information, and to update the copied state information based on a result of collating the second character information with the searching character information.

Abstract: A generation apparatus includes a processor configured to generate existence information indicating that character information including a plurality of continuing characters is included in the file, and in a case that first adscript designation and second adscript designation following to the first adscript designation are included in the file, the first adscript designation designating that first character information is written down with second character information, the second adscript designation designating that third character information is written down with fourth character information, generate another existence information indicating that another character information, which includes an end part of the first character information and a head part of the fourth character information following the end part, is included in the file.

Abstract: A recording medium stores therein an information retrieval program that causes a computer to execute generating a Huffman tree based on an XML tag written in an XML file and an appearance frequency of character data exclusive of the XML tag; compressing the XML file using the Huffman tree; receiving a retrieval condition that includes a retrieval keyword and type information concerning the retrieval keyword; setting a decompression start flag for a compression code that is for an XML start tag related to the type information, the decompression start flag instructing commencement of decompression of a compression code string subsequent to the XML start tag; detecting, in the compressed XML file, the compression code for which the decompression start flag has been set; and decompressing, when the compression code for which the decompression start flag has been set is detected, the compression code string, using the Huffman tree.

Abstract: A decompression apparatus includes a memory configured to store a dictionary data including, in association with a compression code, a decompression symbol and address information indicating a position of flag information, which indicates whether the decompressed symbol is included in a block of decompressed data obtained by decompressing a block of compressed data or not, and a processor configured to execute a procedure, the procedure including accessing the dictionary data stored in the memory, obtaining, from the dictionary data, the decompressed symbol and the address information associated with the compressed symbol included in the block of compressed data, generating the decompressed data by using the obtained decompressed symbol, and updating the flag information stored at the position indicated by the obtained address information.

Abstract: A recording medium stores an information processing program that causes a computer to execute storing a compression symbol map group having a bit string indicating for each character code, presence or absence of the character code in a file group, and a Huffman tree whose leaf corresponding to the character code has a pointer to a compression symbol map of the character code, the Huffman tree converting the character code into a compression symbol of the character code; compressing sequentially and according to the Huffman tree, a character code to be compressed and described in a file of the file group; detecting access to the leaf at the compressing; identifying by a pointer in the accessed leaf, a compression symbol map of the character code to be compressed; and updating a bit that indicates presence or absence of the character code to be compressed, in the identified compression symbol map.

Abstract: An extracting method includes storing to a storage device: files that include character units; first index information indicating which file includes at least one character unit in a character unit group having a usage frequency less than a predetermined frequency and among character units having common information in a predetermined portion, the usage frequency indicating the extent of files having a given character unit; second index information indicating which file includes a first character unit having a usage frequency at least equal to the predetermined frequency and among the character units having common information in a predetermined portion; and referring to the first and second index information to extract a file having character units in the first and second index information, when a request is received for extraction of a file having the first character unit and a second character unit that is included in the character unit group.

Abstract: An encrypting method including encrypting a first data segment of encryption target data on the basis of first key information, generating second key information on the basis of the first data segment by using a predetermined algorithm, and encrypting a second data segment of the encryption target data, which is different from the first data segment, on the basis of the second key information.

Abstract: A recording medium stores an information processing program that causes a computer to execute storing a compression symbol map group having a bit string indicating for each character code, presence or absence of the character code in a file group, and a Huffman tree whose leaf corresponding to the character code has a pointer to a compression symbol map of the character code, the Huffman tree converting the character code into a compression symbol of the character code; compressing sequentially and according to the Huffman tree, a character code to be compressed and described in a file of the file group; detecting access to the leaf at the compressing; identifying by a pointer in the accessed leaf, a compression symbol map of the character code to be compressed; and updating a bit that indicates presence or absence of the character code to be compressed, in the identified compression symbol map.

Abstract: An information retrieval apparatus includes an acquiring unit that acquires a numerical value defining a boundary of a numerical range; a detecting unit that detects a number of places in and a head numeral of the numerical value; an extracting unit that extracts from a bit string group, a bit string indicating whether a numerical value in a numerical value group having the number of places and the head numeral is present in files subject to retrieval; a specifying unit that specifies a file corresponding to a bit in the extracted bit string, the bit indicating the presence of a numerical value of the numerical value group; a determining unit that determines whether a numerical value in the specified file meets the boundary condition; and a designating unit that, based on a determination by the determining unit designates the specified file to have a numerical value within the numerical range.

Abstract: An information retrieval apparatus includes an acquiring unit that acquires a numerical value defining a boundary of a numerical range; a detecting unit that detects a number of places in and a head numeral of the numerical value; an extracting unit that extracts from a bit string group, a bit string indicating whether a numerical value in a numerical value group having the number of places and the head numeral is present in files subject to retrieval; a specifying unit that specifies a file corresponding to a bit in the extracted bit string, the bit indicating the presence of a numerical value of the numerical value group; a determining unit that determines whether a numerical value in the specified file meets the boundary condition; and a designating unit that, based on a determination by the determining unit designates the specified file to have a numerical value within the numerical range.

Abstract: A computer-readable recording medium stores therein an information searching program that causes a computer having access to archives including a compressed file group of compressed files that are to be searched and that have described therein character strings, to execute: sorting the compressed files in descending order of access frequency of the compressed files; combining the compressed files in descending order of access frequency after the sorting at the sorting such that a storage capacity of a cache area for a storage area that stores therein the compressed file group is not exceeded by a combined size of the compressed files combined; and writing, from the storage area into the cache area, the compressed files combined at the combining, the compressed files combined being written prior to a search of the compressed files combined.

Abstract: A computer-readable, non-transitory medium stores a program that manages compressed file groups on a plurality of slave servers. The file groups include compressed files that are to be searched and have character strings. Each of the compressed file groups is expanded, using a Huffman tree that was used for compressing the compressed file group. A common compression parameter is generated based on appearance frequency, by summing, for each character, the appearance frequency in each of the compressed file groups. The expanded files are recompressed using the common Huffman tree such that sums of the access frequencies of the compressed files that are origins of the recompressed files are substantially equivalent among various slave servers. New archives including the re-compressed files are transmitted to the respective slave servers.

Abstract: A recording medium stores an information processing program that causes a computer having a storage unit storing therein a file group in which character code strings are described, to execute generating combined identification information by dividing into two portions, at least one among identification information for a preceding character code and identification information for a succeeding character code and respectively combining the portions with the identification information that is not divided, the preceding and succeeding character codes constituting a character code string for two-consecutive grams in a file among the file group; storing to the storage unit, various consecutive-gram divided maps obtained by allocating to each type of combined identification information generated, a string of bits corresponding to the quantity of files in the file group; and updating in the consecutive-gram divided maps, a bit indicating whether the character code string for the two-consecutive grams is present in the

Abstract: A recording medium stores an information processing program that causes a computer to execute storing a compression symbol map group having a bit string indicating for each character code, presence or absence of the character code in a file group, and a Huffman tree whose leaf corresponding to the character code has a pointer to a compression symbol map of the character code, the Huffman tree converting the character code into a compression symbol of the character code; compressing sequentially and according to the Huffman tree, a character code to be compressed and described in a file of the file group; detecting access to the leaf at the compressing; identifying by a pointer in the accessed leaf, a compression symbol map of the character code to be compressed; and updating a bit that indicates presence or absence of the character code to be compressed, in the identified compression symbol map.

Abstract: A computer-readable recording medium stores therein an information processing program that causes a computer to execute storing an aggregate of layers of nodes respectively having a pointer to an upper node, pointers to a leaf and/or a lower node and branches to lower nodes; obtaining a totaling result of appearance frequencies of character codes described in a file; classifying the character codes by layer, based on appearance probabilities thereof and the totaling result; calculating, based on a quantity of character codes in an ith layer and for the ith layer, a quantity of pointers pointing to leaves, and based on the quantity calculated and for the ith layer, further calculating a number of times nodes are used and a quantity of pointers pointing to lower nodes; generating, based on calculation results, a Huffman tree; and converting the Huffman tree into a node-less Huffman tree and storing the node-less Huffman tree.