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Sync specification with code.

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Natalia Portillo
2025-10-11 13:17:26 +01:00
parent 1f33de2ccf
commit e2f3323a04
17 changed files with 188 additions and 275 deletions
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docs/spec/blocks/header.adoc
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@@ -12,40 +12,23 @@ All subsequent parsing and interpretation of the file depends on the contents of
/**Header, at start of file */
typedef struct AaruHeaderV2
{
/**Header identifier, see AARU_MAGIC */
uint64_t identifier;
/**UTF-16LE name of the application that created the image */
uint8_t application[HEADER_APP_NAME_LEN];
/**Image format major version. A new major version means a possibly incompatible change of format */
uint8_t imageMajorVersion;
/**Image format minor version. A new minor version indicates a compatible change of format */
uint8_t imageMinorVersion;
/**Major version of the application that created the image */
uint8_t applicationMajorVersion;
/**Minor version of the application that created the image */
uint8_t applicationMinorVersion;
/**Type of media contained on image */
uint32_t mediaType;
/**Offset to index */
uint64_t indexOffset;
/**Windows filetime (100 nanoseconds since 1601/01/01 00:00:00 UTC) of image creation time */
int64_t creationTime;
/**Windows filetime (100 nanoseconds since 1601/01/01 00:00:00 UTC) of image last written time */
int64_t lastWrittenTime;
/**Unique identifier that allows children images to recognize and find this image */
uint8_t guid[GUID_SIZE];
/**Block alignment shift. All blocks in the image are aligned at 2 << blockAlignmentShift bytes */
uint8_t blockAlignmentShift;
/**Data shift. All data blocks in the image contain 2 << dataShift items at most */
uint8_t dataShift;
/**Table shift. All deduplication tables in the image use this shift to calculate the position of an item */
uint8_t tableShift;
/**Features used in this image that if unsupported are still compatible for reading and writing implementations */
uint64_t featureCompatible;
/**Features used in this image that if unsupported are still compatible for reading implementations but not for writing */
uint64_t featureCompatibleRo;
/**Features used in this image that if unsupported prevent reading or writing the image */
uint64_t featureIncompatible;
uint64_t identifier; ///< File magic (AARU_MAGIC).
uint8_t application[AARU_HEADER_APP_NAME_LEN]; ///< UTF-8 creator application name (fixed 64 bytes).
uint8_t imageMajorVersion; ///< Container format major version.
uint8_t imageMinorVersion; ///< Container format minor version.
uint8_t applicationMajorVersion; ///< Creator application major version.
uint8_t applicationMinorVersion; ///< Creator application minor / patch version.
uint32_t mediaType; ///< Media type enumeration (value from \ref MediaType).
uint64_t indexOffset; ///< Absolute byte offset to primary index block (MUST be > 0; 0 => corrupt/unreadable).
int64_t creationTime; ///< Creation FILETIME (100 ns since 1601-01-01 UTC).
int64_t lastWrittenTime; ///< Last modification FILETIME (100 ns since 1601-01-01 UTC).
uint8_t guid[GUID_SIZE]; ///< 128-bit image GUID (binary, not text); stable across children.
uint8_t blockAlignmentShift; ///< log2 block alignment (block size alignment = 2^blockAlignmentShift bytes).
uint8_t dataShift; ///< log2 sectors/items per block-index increment in DDT entries (2^dataShift).
uint8_t tableShift; ///< log2 sectors spanned by each primary DDT entry (0 = single-level).
uint64_t featureCompatible; ///< Feature bits: unimplemented bits are ignorable (still R/W safe).
uint64_t featureCompatibleRo; ///< Feature bits: unimplemented -> degrade to read-only access.
uint64_t featureIncompatible; ///< Feature bits: any unimplemented -> abort (cannot open safely).
} AaruHeaderV2;
=== Field Descriptions