The blog post details the reverse engineering process of Apple's proprietary Typed Stream format used in various macOS features like Spotlight search indexing and QuickLook previews. The author, motivated by the lack of public documentation, utilizes a combination of tools and techniques including analyzing generated Typed Stream files, using class-dump on relevant system frameworks, and examining open-source components like CoreFoundation, to decipher the format. They ultimately discover that Typed Streams are essentially serialized property lists with a specific header and optional compression, allowing for efficient storage and retrieval of typed data. This reverse engineering effort provides valuable insight into the inner workings of macOS and potentially enables interoperability with other systems.
Startifact's blog post details the perplexing disappearance and reappearance of Quentell, a critical dependency used in their Elixir projects. After vanishing from Hex, the package manager for Elixir, the team scrambled to understand the situation. They discovered the package owner had accidentally deleted it while attempting to transfer ownership. Despite the accidental nature of the deletion, Hex lacked a readily available undelete or restore feature, forcing Startifact to explore workarounds. They ultimately republished Quentell under their own organization, forking it and incrementing the version number to ensure project compatibility. The incident highlighted the fragility of software supply chains and the need for robust backup and recovery mechanisms in package management systems.
Hacker News users discussed the lack of transparency and questionable practices surrounding Quentell, the mysterious figure behind Startifact and other ventures. Several commenters expressed skepticism about the purported accomplishments and the overall narrative presented in the blog post, with some suggesting it reads like a fabricated story. The secrecy surrounding Quentell's identity and the lack of verifiable information fueled speculation about potential ulterior motives, ranging from a marketing ploy to something more nefarious. The most compelling comments highlighted the unusual nature of the story and the lack of evidence to support the claims made, raising concerns about the credibility of the entire narrative. Some users also pointed out inconsistencies and contradictions within the blog post itself, further contributing to the overall sense of distrust.
Summary of Comments ( 14 )
https://news.ycombinator.com/item?id=42919221
HN users generally praised the author's reverse-engineering effort, calling it "impressive" and "well-documented." Some discussed the implications of Apple using a custom format, speculating about potential performance benefits or tighter integration with their hardware. One commenter noted the similarity to Google's Protocol Buffers, suggesting Apple might have chosen this route to avoid dependencies. Others pointed out the difficulty in reverse-engineering these formats, highlighting the value of such work for interoperability. A few users discussed potential use cases for the information, including debugging and data recovery. Some also questioned the long-term viability of relying on undocumented formats.
The Hacker News post titled "Reverse Engineering Apple's typedstream Format," linking to an article detailing the reverse engineering process of Apple's TypedStream format, sparked a moderately active discussion with several insightful comments.
One commenter highlights the complexity and undocumented nature of the TypedStream format, expressing surprise that the author managed to decode it without access to internal Apple documentation. They commend the author's effort, noting the value in understanding such proprietary formats for interoperability.
Another commenter focuses on the potential applications of this reverse engineering effort, specifically mentioning the possibility of improving data transfer between Apple devices and other platforms. They suggest that a well-documented open-source implementation of TypedStream could be highly beneficial.
A further comment delves into the intricacies of Apple's software ecosystem, pointing out the historical prevalence of proprietary formats within macOS and iOS. They discuss how these formats, while often efficient and well-designed, can create hurdles for developers working outside the Apple ecosystem. This commenter also touches upon Apple's gradual shift towards more open standards in recent years.
One user questions the long-term stability of relying on reverse-engineered formats, given Apple's potential to change the TypedStream format without notice. They suggest that any tools built based on this reverse engineering work might break with future macOS or iOS updates. This comment highlights the inherent risks associated with relying on undocumented functionalities.
Another commenter offers a more technical perspective, discussing the specific challenges of reverse engineering binary formats like TypedStream. They mention the importance of using tools like disassemblers and debuggers to understand the underlying data structures and algorithms.
Finally, a commenter praises the clear and detailed explanation provided in the blog post, appreciating the author's step-by-step approach to the reverse engineering process. They express interest in seeing further analysis and potential tooling developed based on this research.
The overall sentiment in the comments is one of appreciation for the author's work, mixed with pragmatic concerns about the challenges and limitations of working with reverse-engineered proprietary formats. The discussion highlights the importance of such efforts for fostering interoperability and understanding the complexities of closed ecosystems.