handle message unknown charset error - aerc - mirror of ~rjarry's aerc fork

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author	Jeff Martin <jeffmartin@gmail.com>	2020-08-21 11:58:30 -0700
committer	Reto Brunner <reto@labrat.space>	2020-08-31 22:00:28 +0200
commit	0acb28645fe73d488b82d2915add6c262028bbe3 (patch)
tree	cd197771f4172e2da75c9fec6c5862cd377d7b51 /worker/maildir/container.go
parent	43c4f2f3ab8bd914ce1b5c1841724f3c55550e9c (diff)
download	aerc-0acb28645fe73d488b82d2915add6c262028bbe3.tar.gz

handle message unknown charset error

This change handles message parse errors by printing the error when the
user tries to view the message. Specifically only handling unknown
charset errors in this patch, but there are many types of invalid
messages that can be handled in this way.

aerc currently leaves certain messages in the msglist in the pending
(spinner) state, and I'm unable to view or modify the message. aerc also
only prints parse errors with message when they are initially loaded.
This UX is a little better, because you can still see the header info
about the message, and if you try to view it, you will see the specific
error.

Diffstat (limited to 'worker/maildir/container.go')

0 files changed, 0 insertions, 0 deletions

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Mu - 034address.cc</title> <meta name="Generator" content="Vim/7.4"> <meta name="plugin-version" content="vim7.4_v2"> <meta name="syntax" content="cpp"> <meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy="> <meta name="colorscheme" content="minimal"> <style type="text/css">  </style> <script type='text/javascript'>  </script> </head> <body> <pre id='vimCodeElement'> //: Addresses help us spend less time copying data around. //: So far we've been operating on primitives like numbers and characters, and //: we've started combining these primitives together into larger logical //: units (containers or arrays) that may contain many different primitives at //: once. Containers and arrays can grow quite large in complex programs, and //: we'd like some way to efficiently share them between recipes without //: constantly having to make copies. Right now 'next-ingredient' and 'reply' //: copy data across recipe boundaries. To avoid copying large quantities of //: data around, we'll use *addresses*. An address is a bookmark to some //: arbitrary quantity of data (the *payload*). It's a primitive, so it's as //: efficient to copy as a number. To read or modify the payload 'pointed to' //: by an address, we'll perform a *lookup*. //: //: The notion of 'lookup' isn't an instruction like 'add' or 'subtract'. //: Instead it's an operation that can be performed when reading any of the //: ingredients of an instruction, and when writing to any of the products. To //: write to the payload of an ingredient rather than its value, simply add //: the /lookup property to it. Modern computers provide efficient support for //: addresses and lookups, making this a realistic feature. //: //: To recap: an address is a bookmark to some potentially large payload, and //: you can replace any ingredient or product with a lookup to an address of //: the appropriate type. But how do we get addresses to begin with? That //: requires a little more explanation. Once we introduce the notion of //: bookmarks to data, we have to think about the life cycle of a piece of //: data and its bookmarks (because remember, bookmarks can be copied around //: just like anything else). Otherwise several bad outcomes can result (and //: indeed *have* resulted in past languages like C): //: //: a) You can run out of memory if you don't have a way to reclaim //: data. //: b) If you allow data to be reclaimed, you have to be careful not to //: leave any stale addresses pointing at it. Otherwise your program might //: try to lookup such an address and find something unexpected. Such //: problems can be very hard to track down, and they can also be exploited //: to break into your computer over the network, etc. //: //: To avoid these problems, we introduce the notion of a *reference count* or //: refcount. The life cycle of a bit of data accessed through addresses looks //: like this. //: //: We create space in computer memory for it using the 'new' instruction. //: The 'new' instruction takes a type as an ingredient, allocates //: sufficient space to hold that type, and returns an address (bookmark) //: to the allocated space. //: //: x:address:number <- new number:type //: //: +------------+ //: x -------> | number | //: +------------+ //: //: That isn't entirely accurate. Under the hood, 'new' allocates an extra //: number -- the refcount: //: //: +------------+------------+ //: x -------> | refcount | number | //: +------------+------------+ //: //: This probably seems like a waste of space. In practice it isn't worth //: allocating individual numbers and our payload will tend to be larger, //: so the picture would look more like this (zooming out a bit): //: //: +-------------------------+ //: +---+ | //: x -------> | r | | //: +---+ DATA | //: | | //: | | //: +-------------------------+ //: //: (Here 'r' denotes the refcount. It occupies a tiny amount of space //: compared to the payload.) //: //: Anyways, back to our example where the data is just a single number. //: After the call to 'new', Mu's map of memory looks like this: //: //: +---+------------+ //: x -------> | 1 | number | //: +---+------------+ //: //: The refcount of 1 here indicates that this number has one bookmark //: outstanding. If you then make a copy of x, the refcount increments: //: //: y:address:number <- copy x //: //: x ---+ +---+------------+ //: +---> | 2 | number | //: y ---+ +---+------------+ //: //: Whether you access the payload through x or y, Mu knows how many //: bookmarks are outstanding to it. When you change x or y, the refcount //: transparently decrements: //: //: x <- copy 0 # an address is just a number, you can always write 0 to it //: //: +---+------------+ //: y -------> | 1 | number | //: +---+------------+ //: //: The final flourish is what happens when the refcount goes down to 0: Mu //: reclaims the space occupied by both refcount and payload in memory, and //: they're ready to be reused by later calls to 'new'. //: //: y <- copy 0 //: //: +---+------------+ //: | 0 | XXXXXXX | //: +---+------------+ //: //: Using refcounts fixes both our problems a) and b) above: you can use //: memory for many different purposes as many times as you want without //: running out of memory, and you don't have to worry about ever leaving a //: dangling bookmark when you reclaim memory. //: //: This layer implements creating addresses using 'new'. The next few layers //: will flesh out the rest of the life cycle. //: //: The tests in this layer use unsafe operations so as to stay decoupled from //: 'new'. //: todo: give 'new' a custodian ingredient. Following malloc/free is a temporary hack. :(scenario new) # call 'new' two times with identical types without modifying the results; you # should get back different results def main [ 1:address:number/raw <- new number:type 2:address:number/raw <- new number:type 3:boolean/raw <- equal 1:address:number/raw, 2:address:number/raw ] +mem: storing 0 in location 3 :(scenario dilated_reagent_with_new) def main [ 1:address:address:number <- new {(address number): type} ] +new: size of ("address" "number") is 1 //: 'new' takes a weird 'type' as its first ingredient; don't error on it :(before "End Mu Types Initialization") put(Type_ordinal, "type", 0); :(code) bool is_mu_type_literal(const reagent& r) { return is_literal(r) && r.type && r.type->name == "type"; } :(before "End Primitive Recipe Declarations") NEW, :(before "End Primitive Recipe Numbers") put(Recipe_ordinal, "new", NEW); :(before "End Primitive Recipe Checks") case NEW: { const recipe& caller = get(Recipe, r); if (inst.ingredients.empty() || SIZE(inst.ingredients) > 2) { raise << maybe(caller.name) << "'new' requires one or two ingredients, but got '" << to_original_string(inst) << "'\n" << end(); break; } // End NEW Check Special-cases const reagent& type = inst.ingredients.at(0); if (!is_mu_type_literal(type)) { raise << maybe(caller.name) << "first ingredient of 'new' should be a type, but got '" << type.original_string << "'\n" << end(); break; } if (inst.products.empty()) { raise << maybe(caller.name) << "result of 'new' should never be ignored\n" << end(); break; } if (!product_of_new_is_valid(inst)) { raise << maybe(caller.name) << "product of 'new' has incorrect type: '" << to_original_string(inst) << "'\n" << end(); break; } break; } :(code) bool product_of_new_is_valid(const instruction& inst) { reagent/*copy*/ product = inst.products.at(0); // Update NEW product in Check if (!product.type || product.type->value != get(Type_ordinal, "address")) return false; drop_from_type(product, "address"); if (SIZE(inst.ingredients) > 1) { // array allocation if (!product.type || product.type->value != get(Type_ordinal, "array")) return false; drop_from_type(product, "array"); } reagent/*copy*/ expected_product("x:"+inst.ingredients.at(0).name); { string_tree* tmp_type_names = parse_string_tree(expected_product.type->name); delete expected_product.type; expected_product.type = new_type_tree(tmp_type_names); delete tmp_type_names; } return types_strictly_match(product, expected_product); } void drop_from_type(reagent& r, string expected_type) { if (r.type->name != expected_type) { raise << "can't drop2 " << expected_type << " from '" << to_string(r) << "'\n" << end(); return; } type_tree* tmp = r.type; r.type = tmp->right; tmp->right = NULL; delete tmp; } //: To implement 'new', a Mu transform turns all 'new' instructions into //: 'allocate' instructions that precompute the amount of memory they want to //: allocate. //: Ensure that we never call 'allocate' directly, and that there's no 'new' //: instructions left after the transforms have run. :(before "End Primitive Recipe Checks") case ALLOCATE: { raise << "never call 'allocate' directly'; always use 'new'\n" << end(); break; } :(before "End Primitive Recipe Implementations") case NEW: { raise << "no implementation for 'new'; why wasn't it translated to 'allocate'? Please save a copy of your program and send it to Kartik.\n" << end(); break; } :(after "Transform.push_back(check_instruction)") // check_instruction will guard against direct 'allocate' instructions below Transform.push_back(transform_new_to_allocate); // idempotent :(code) void transform_new_to_allocate(const recipe_ordinal r) { trace(9991, "transform") << "--- convert 'new' to 'allocate' for recipe " << get(Recipe, r).name << end(); for (int i = 0; i < SIZE(get(Recipe, r).steps); ++i) { instruction& inst = get(Recipe, r).steps.at(i); // Convert 'new' To 'allocate' if (inst.name == "new") { inst.operation = ALLOCATE; string_tree* type_name = new string_tree(inst.ingredients.at(0).name); type_name = parse_string_tree(type_name); type_tree* type = new_type_tree(type_name); inst.ingredients.at(0).set_value(size_of(type)); trace(9992, "new") << "size of " << to_string(type_name) << " is " << inst.ingredients.at(0).value << end(); delete type; delete type_name; } } } //: implement 'allocate' based on size :(before "End Globals") const int Reserved_for_tests = 1000; int Memory_allocated_until = Reserved_for_tests; int Initial_memory_per_routine = 100000; :(before "End Setup") Memory_allocated_until = Reserved_for_tests; Initial_memory_per_routine = 100000; :(before "End routine Fields") int alloc, alloc_max; :(before "End routine Constructor") alloc = Memory_allocated_until; Memory_allocated_until += Initial_memory_per_routine; alloc_max = Memory_allocated_until; trace(9999, "new") << "routine allocated memory from " << alloc << " to " << alloc_max << end(); :(before "End Primitive Recipe Declarations") ALLOCATE, :(before "End Primitive Recipe Numbers") put(Recipe_ordinal, "allocate", ALLOCATE); :(before "End Primitive Recipe Implementations") case ALLOCATE: { // compute the space we need int size = ingredients.at(0).at(0); if (SIZE(ingredients) > 1) { // array allocation trace(9999, "mem") << "array size is " << ingredients.at(1).at(0) << end(); size = /*space for length*/1 + size*ingredients.at(1).at(0); } // include space for refcount size++; trace(9999, "mem") << "allocating size " << size << end(); //? Total_alloc += size; //? Num_alloc++; // compute the region of memory to return // really crappy at the moment ensure_space(size); const int result = Current_routine->alloc; trace(9999, "mem") << "new alloc: " << result << end(); // save result products.resize(1); products.at(0).push_back(result); // initialize allocated space for (int address = result; address < result+size; ++address) { trace(9999, "mem") << "storing 0 in location " << address << end(); put(Memory, address, 0); } if (SIZE(current_instruction().ingredients) > 1) { // initialize array length trace(9999, "mem") << "storing " << ingredients.at(1).at(0) << " in location " << result+/*skip refcount*/1 << end(); put(Memory, result+/*skip refcount*/1, ingredients.at(1).at(0)); } Current_routine->alloc += size; // no support yet for reclaiming memory between routines assert(Current_routine->alloc <= Current_routine->alloc_max); break; } //: statistics for debugging //? :(before "End Globals") //? int Total_alloc = 0; //? int Num_alloc = 0; //? int Total_free = 0; //? int Num_free = 0; //? :(before "End Setup") //? Total_alloc = Num_alloc = Total_free = Num_free = 0; //? :(before "End Teardown") //? cerr << Total_alloc << "/" << Num_alloc //? << " vs " << Total_free << "/" << Num_free << '\n'; //? cerr << SIZE(Memory) << '\n'; :(code) void ensure_space(int size) { if (size > Initial_memory_per_routine) { tb_shutdown(); cerr << "can't allocate " << size << " locations, that's too much compared to " << Initial_memory_per_routine << ".\n"; exit(0); } if (Current_routine->alloc + size > Current_routine->alloc_max) { // waste the remaining space and create a new chunk Current_routine->alloc = Memory_allocated_until; Memory_allocated_until += Initial_memory_per_routine; Current_routine->alloc_max = Memory_allocated_until; trace(9999, "new") << "routine allocated memory from " << Current_routine->alloc << " to " << Current_routine->alloc_max << end(); } } :(scenario new_initializes) % Memory_allocated_until = 10; % put(Memory, Memory_allocated_until, 1); def main [ 1:address:number <- new number:type ] +mem: storing 0 in location 10 :(scenario new_array) def main [ 1:address:array:number/raw <- new number:type, 5 2:address:number/raw <- new number:type 3:number/raw <- subtract 2:address:number/raw, 1:address:array:number/raw ] +run: {1: ("address" "array" "number"), "raw": ()} <- new {number: "type"}, {5: "literal"} +mem: array size is 5 # don't forget the extra location for array size, and the second extra location for the refcount +mem: storing 7 in location 3 :(scenario new_empty_array) def main [ 1:address:array:number/raw <- new number:type, 0 2:address:number/raw <- new number:type 3:number/raw <- subtract 2:address:number/raw, 1:address:array:number/raw ] +run: {1: ("address" "array" "number"), "raw": ()} <- new {number: "type"}, {0: "literal"} +mem: array size is 0 # one location for array size, and one for the refcount +mem: storing 2 in location 3 //: If a routine runs out of its initial allocation, it should allocate more. :(scenario new_overflow) % Initial_memory_per_routine = 3; // barely enough room for point allocation below def main [ 1:address:number/raw <- new number:type 2:address:point/raw <- new point:type # not enough room in initial page ] +new: routine allocated memory from 1000 to 1003 +new: routine allocated memory from 1003 to 1006 </pre> </body> </html>


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