support sparse flag

[iamr0s]

ResourcesType.h (Android 7.1.2):

struct ResTable_type
{
    struct ResChunk_header header;

    enum {
        NO_ENTRY = 0xFFFFFFFF
    };
    
    // The type identifier this chunk is holding.  Type IDs start
    // at 1 (corresponding to the value of the type bits in a
    // resource identifier).  0 is invalid.
    uint8_t id;
    
    // Must be 0.
    uint8_t res0;
    // Must be 0.
    uint16_t res1;
    
    // Number of uint32_t entry indices that follow.
    uint32_t entryCount;

    // Offset from header where ResTable_entry data starts.
    uint32_t entriesStart;
    
    // Configuration this collection of entries is designed for.
    ResTable_config config;
};

Resources.h (Android 8.0.0):

struct ResTable_type
{
    struct ResChunk_header header;

    enum {
        NO_ENTRY = 0xFFFFFFFF
    };
    
    // The type identifier this chunk is holding.  Type IDs start
    // at 1 (corresponding to the value of the type bits in a
    // resource identifier).  0 is invalid.
    uint8_t id;
    
    enum {
        // If set, the entry is sparse, and encodes both the entry ID and offset into each entry,
        // and a binary search is used to find the key. Only available on platforms >= O.
        // Mark any types that use this with a v26 qualifier to prevent runtime issues on older
        // platforms.
        FLAG_SPARSE = 0x01,
    };
    uint8_t flags;

    // Must be 0.
    uint16_t reserved;
    
    // Number of uint32_t entry indices that follow.
    uint32_t entryCount;

    // Offset from header where ResTable_entry data starts.
    uint32_t entriesStart;

    // Configuration this collection of entries is designed for. This must always be last.
    ResTable_config config;
};

If set, we can read it by this way:

val offsetMap = mutableMapOf<Int, Int>()
for (i in 0 until header.entryCount)
    offsetMap[i] = reader.int

If set, the entry is sparse, and encodes both the entry ID and offset into each entry, so we can read it by this way

val offsetMap = mutableMapOf<Int, Int>()
for (i in 0 until header.entryCount)
    if (header.flags.isSparse) offsetMap[reader.uShort.toInt()] = (reader.uShort * 4u).toInt()
    else offsetMap[i] = reader.int

when FLAG_SPARSE is not set, we can get offset by read a int.
when FLAG_SPARSE is set, we can get entry id by read a unsigned short, then get offset by read a unsigned short;

[iBotPeaches]

Thanks for details and patch. I've kicked off CI process and will return to review more thoroughly.

[iBotPeaches]

thanks!